diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 60f882231bc..3f72f5ffe0c 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -989,6 +989,106 @@ testdb=>
+
+ \crosstabview [
+ colV
+ colH
+ [:scolH]
+ [colD]
+ ]
+
+
+ Execute the current query buffer (like \g) and shows
+ the results inside a crosstab grid.
+ The query must return at least three columns.
+ The output column colV
+ becomes a vertical header
+ and the output column colH
+ becomes a horizontal header, optionally sorted by ranking data obtained
+ from scolH.
+ colD
+ is the output column to project into the grid. If this is not
+ specified and there are exactly three columns in the result set,
+ the column that isn't
+ colV nor
+ colH
+ is displayed; if there are more columns, an error is thrown.
+
+
+
+ All columns can be refered to by their position (starting at 1), or by
+ their name. Normal case folding and quoting rules apply on column
+ names. By default,
+ colV corresponds to column 1
+ and colH to column 2.
+ A query having only one output column cannot be viewed in crosstab, and
+ colH must differ from
+ colV.
+
+
+
+ The vertical header, displayed as the leftmost column,
+ contains the deduplicated values found in
+ column colV, in the same
+ order as in the query results.
+
+
+
+ The horizontal header, displayed as the first row,
+ contains the deduplicated values found in
+ column colH, in
+ the order of appearance in the query results.
+ If specified, the optional scolH
+ argument refers to a column whose values should be integer numbers
+ by which colH will be sorted
+ to be positioned in the horizontal header.
+
+
+
+ Inside the crosstab grid,
+ given a query output with N columns
+ (including colV and
+ colH),
+ for each distinct value x of
+ colH
+ and each distinct value y of
+ colV,
+ the contents of a cell located at the intersection
+ (x,y) is determined by these rules:
+
+
+
+ if there is no corresponding row in the query results such that the
+ value for colH
+ is x and the value
+ for colV
+ is y, the cell is empty.
+
+
+
+
+
+ if there is exactly one row such that the value
+ for colH
+ is x and the value
+ for colV
+ is y, then the colD column
+ is displayed.
+
+
+
+
+
+ if there are several such rows, an error is thrown.
+
+
+
+
+
+
+
+
+
\d[S+] [ pattern ]
@@ -4070,6 +4170,47 @@ first | 4
second | four
+
+ When suitable, query results can be shown in a crosstab representation
+ with the \crosstabview command:
+
+testdb=> SELECT first, second, first > 2 AS gt2 FROM my_table;
+ first | second | ge2
+-------+--------+-----
+ 1 | one | f
+ 2 | two | f
+ 3 | three | t
+ 4 | four | t
+(4 rows)
+
+testdb=> \crosstabview first second
+ first | one | two | three | four
+-------+-----+-----+-------+------
+ 1 | f | | |
+ 2 | | f | |
+ 3 | | | t |
+ 4 | | | | t
+(4 rows)
+
+
+This second example shows a multiplication table with rows sorted in reverse
+numerical order and columns with an independant, ascending numerical order.
+
+testdb=> SELECT t1.first as "A", t2.first+100 AS "B", t1.first*(t2.first+100) as "AxB",
+testdb(> row_number() over(order by t2.first) AS ord
+testdb(> FROM my_table t1 CROSS JOIN my_table t2 ORDER BY 1 DESC
+testdb(> \crosstabview A B:ord AxB
+ A | 101 | 102 | 103 | 104
+---+-----+-----+-----+-----
+ 4 | 404 | 408 | 412 | 416
+ 3 | 303 | 306 | 309 | 312
+ 2 | 202 | 204 | 206 | 208
+ 1 | 101 | 102 | 103 | 104
+(4 rows)
+
+
+
+
diff --git a/src/bin/psql/Makefile b/src/bin/psql/Makefile
index d1c3b777c25..1f6a289ea09 100644
--- a/src/bin/psql/Makefile
+++ b/src/bin/psql/Makefile
@@ -23,7 +23,7 @@ LDFLAGS += -L$(top_builddir)/src/fe_utils -lpgfeutils -lpq
OBJS= command.o common.o help.o input.o stringutils.o mainloop.o copy.o \
startup.o prompt.o variables.o large_obj.o describe.o \
- tab-complete.o \
+ crosstabview.o tab-complete.o \
sql_help.o psqlscanslash.o \
$(WIN32RES)
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 9eae76f7ba8..227d1805d44 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -39,6 +39,7 @@
#include "common.h"
#include "copy.h"
+#include "crosstabview.h"
#include "describe.h"
#include "help.h"
#include "input.h"
@@ -364,6 +365,20 @@ exec_command(const char *cmd,
else if (strcmp(cmd, "copyright") == 0)
print_copyright();
+ /* \crosstabview -- execute a query and display results in crosstab */
+ else if (strcmp(cmd, "crosstabview") == 0)
+ {
+ pset.ctv_col_V = psql_scan_slash_option(scan_state,
+ OT_NORMAL, NULL, false);
+ pset.ctv_col_H = psql_scan_slash_option(scan_state,
+ OT_NORMAL, NULL, false);
+ pset.ctv_col_D = psql_scan_slash_option(scan_state,
+ OT_NORMAL, NULL, false);
+
+ pset.crosstab_flag = true;
+ status = PSQL_CMD_SEND;
+ }
+
/* \d* commands */
else if (cmd[0] == 'd')
{
diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index df3441cc750..437cb568234 100644
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -23,6 +23,7 @@
#include "settings.h"
#include "command.h"
#include "copy.h"
+#include "crosstabview.h"
#include "fe_utils/mbprint.h"
@@ -1064,6 +1065,8 @@ PrintQueryResults(PGresult *results)
success = StoreQueryTuple(results);
else if (pset.gexec_flag)
success = ExecQueryTuples(results);
+ else if (pset.crosstab_flag)
+ success = PrintResultsInCrosstab(results);
else
success = PrintQueryTuples(results);
/* if it's INSERT/UPDATE/DELETE RETURNING, also print status */
@@ -1213,7 +1216,8 @@ SendQuery(const char *query)
}
}
- if (pset.fetch_count <= 0 || pset.gexec_flag || !is_select_command(query))
+ if (pset.fetch_count <= 0 || pset.gexec_flag ||
+ pset.crosstab_flag || !is_select_command(query))
{
/* Default fetch-it-all-and-print mode */
instr_time before,
@@ -1356,6 +1360,24 @@ sendquery_cleanup:
/* reset \gexec trigger */
pset.gexec_flag = false;
+ /* reset \crosstabview trigger */
+ pset.crosstab_flag = false;
+ if (pset.ctv_col_V)
+ {
+ free(pset.ctv_col_V);
+ pset.ctv_col_V = NULL;
+ }
+ if (pset.ctv_col_H)
+ {
+ free(pset.ctv_col_H);
+ pset.ctv_col_H = NULL;
+ }
+ if (pset.ctv_col_D)
+ {
+ free(pset.ctv_col_D);
+ pset.ctv_col_D = NULL;
+ }
+
return OK;
}
@@ -1501,7 +1523,7 @@ ExecQueryUsingCursor(const char *query, double *elapsed_msec)
break;
}
- /* Note we do not deal with \gexec mode here */
+ /* Note we do not deal with \gexec or \crosstabview modes here */
ntuples = PQntuples(results);
diff --git a/src/bin/psql/crosstabview.c b/src/bin/psql/crosstabview.c
new file mode 100644
index 00000000000..3d4cf1ac919
--- /dev/null
+++ b/src/bin/psql/crosstabview.c
@@ -0,0 +1,878 @@
+/*
+ * psql - the PostgreSQL interactive terminal
+ *
+ * Copyright (c) 2000-2016, PostgreSQL Global Development Group
+ *
+ * src/bin/psql/crosstabview.c
+ */
+#include "postgres_fe.h"
+
+#include
+
+#include "common.h"
+#include "crosstabview.h"
+#include "pqexpbuffer.h"
+#include "settings.h"
+
+
+/*
+ * Value/position from the resultset that goes into the horizontal or vertical
+ * crosstabview header.
+ */
+typedef struct _pivot_field
+{
+ /*
+ * Pointer obtained from PQgetvalue() for colV or colH. Each distinct
+ * value becomes an entry in the vertical header (colV), or horizontal
+ * header (colH). A Null value is represented by a NULL pointer.
+ */
+ char *name;
+
+ /*
+ * When a sort is requested on an alternative column, this holds
+ * PQgetvalue() for the sort column corresponding to . If
+ * appear multiple times, it's the first value in the order of the results
+ * that is kept. A Null value is represented by a NULL pointer.
+ */
+ char *sort_value;
+
+ /*
+ * Rank of this value, starting at 0. Initially, it's the relative
+ * position of the first appearance of in the resultset. For
+ * example, if successive rows contain B,A,C,A,D then it's B:0,A:1,C:2,D:3
+ * When a sort column is specified, ranks get updated in a final pass to
+ * reflect the desired order.
+ */
+ int rank;
+} pivot_field;
+
+/* Node in avl_tree */
+typedef struct _avl_node
+{
+ /* Node contents */
+ pivot_field field;
+
+ /*
+ * Height of this node in the tree (number of nodes on the longest path to
+ * a leaf).
+ */
+ int height;
+
+ /*
+ * Child nodes. [0] points to left subtree, [1] to right subtree. Never
+ * NULL, points to the empty node avl_tree.end when no left or right
+ * value.
+ */
+ struct _avl_node *children[2];
+} avl_node;
+
+/*
+ * Control structure for the AVL tree (binary search tree kept
+ * balanced with the AVL algorithm)
+ */
+typedef struct _avl_tree
+{
+ int count; /* Total number of nodes */
+ avl_node *root; /* root of the tree */
+ avl_node *end; /* Immutable dereferenceable empty tree */
+} avl_tree;
+
+
+static bool printCrosstab(const PGresult *results,
+ int num_columns, pivot_field *piv_columns, int field_for_columns,
+ int num_rows, pivot_field *piv_rows, int field_for_rows,
+ int field_for_data);
+static int parseColumnRefs(char *arg, PGresult *res, int **col_numbers,
+ int max_columns, char separator);
+static void avlInit(avl_tree *tree);
+static void avlMergeValue(avl_tree *tree, char *name, char *sort_value);
+static int avlCollectFields(avl_tree *tree, avl_node *node,
+ pivot_field *fields, int idx);
+static void avlFree(avl_tree *tree, avl_node *node);
+static void rankSort(int num_columns, pivot_field *piv_columns);
+static int indexOfColumn(const char *arg, PGresult *res);
+static int pivotFieldCompare(const void *a, const void *b);
+static int rankCompare(const void *a, const void *b);
+
+
+/*
+ * Main entry point to this module.
+ *
+ * Process the data from *res according the display options in pset (global),
+ * to generate the horizontal and vertical headers contents,
+ * then call printCrosstab() for the actual output.
+ */
+bool
+PrintResultsInCrosstab(PGresult *res)
+{
+ char *opt_field_for_rows = pset.ctv_col_V;
+ char *opt_field_for_columns = pset.ctv_col_H;
+ char *opt_field_for_data = pset.ctv_col_D;
+ int rn;
+ avl_tree piv_columns;
+ avl_tree piv_rows;
+ pivot_field *array_columns = NULL;
+ pivot_field *array_rows = NULL;
+ int num_columns = 0;
+ int num_rows = 0;
+ int *colsV = NULL,
+ *colsH = NULL,
+ *colsD = NULL;
+ int n;
+ int field_for_columns;
+ int sort_field_for_columns = -1;
+ int field_for_rows;
+ int field_for_data = -1;
+ bool retval = false;
+
+ avlInit(&piv_rows);
+ avlInit(&piv_columns);
+
+ if (res == NULL)
+ {
+ psql_error(_("No result\n"));
+ goto error_return;
+ }
+
+ if (PQresultStatus(res) != PGRES_TUPLES_OK)
+ {
+ psql_error(_("The query must return results to be shown in crosstab\n"));
+ goto error_return;
+ }
+
+ if (opt_field_for_rows && !opt_field_for_columns)
+ {
+ psql_error(_("A second column must be specified for the horizontal header\n"));
+ goto error_return;
+ }
+
+ if (PQnfields(res) <= 2)
+ {
+ psql_error(_("The query must return at least two columns to be shown in crosstab\n"));
+ goto error_return;
+ }
+
+ /*
+ * Arguments processing for the vertical header (1st arg) displayed in the
+ * left-most column. Only a reference to a field is accepted (no sort
+ * column).
+ */
+
+ if (opt_field_for_rows == NULL)
+ {
+ field_for_rows = 0;
+ }
+ else
+ {
+ n = parseColumnRefs(opt_field_for_rows, res, &colsV, 1, ':');
+ if (n != 1)
+ goto error_return;
+ field_for_rows = colsV[0];
+ }
+
+ if (field_for_rows < 0)
+ goto error_return;
+
+ /*----------
+ * Arguments processing for the horizontal header (2nd arg)
+ * (pivoted column that gets displayed as the first row).
+ * Determine:
+ * - the field number for the horizontal header column
+ * - the field number of the associated sort column, if any
+ */
+
+ if (opt_field_for_columns == NULL)
+ field_for_columns = 1;
+ else
+ {
+ n = parseColumnRefs(opt_field_for_columns, res, &colsH, 2, ':');
+ if (n <= 0)
+ goto error_return;
+ if (n == 1)
+ field_for_columns = colsH[0];
+ else
+ {
+ field_for_columns = colsH[0];
+ sort_field_for_columns = colsH[1];
+ }
+
+ if (field_for_columns < 0)
+ goto error_return;
+ }
+
+ if (field_for_columns == field_for_rows)
+ {
+ psql_error(_("The same column cannot be used for both vertical and horizontal headers\n"));
+ goto error_return;
+ }
+
+ /*
+ * Arguments processing for the data columns (3rd arg). Determine the
+ * column to display in the grid.
+ */
+ if (opt_field_for_data == NULL)
+ {
+ int i;
+
+ /*
+ * If the data column was not specified, we search for the one not
+ * used as either vertical or horizontal headers. If the result has
+ * more than three columns, raise an error.
+ */
+ if (PQnfields(res) > 3)
+ {
+ psql_error(_("Data column must be specified when the result set has more than three columns\n"));
+ goto error_return;
+ }
+
+ for (i = 0; i < PQnfields(res); i++)
+ {
+ if (i != field_for_rows && i != field_for_columns)
+ {
+ field_for_data = i;
+ break;
+ }
+ }
+ Assert(field_for_data >= 0);
+ }
+ else
+ {
+ int num_fields;
+
+ /* If a field was given, find out what it is. Only one is allowed. */
+ num_fields = parseColumnRefs(opt_field_for_data, res, &colsD, 1, ',');
+ if (num_fields < 1)
+ goto error_return;
+ field_for_data = colsD[0];
+ }
+
+ /*
+ * First part: accumulate the names that go into the vertical and
+ * horizontal headers, each into an AVL binary tree to build the set of
+ * DISTINCT values.
+ */
+
+ for (rn = 0; rn < PQntuples(res); rn++)
+ {
+ char *val;
+ char *val1;
+
+ /* horizontal */
+ val = PQgetisnull(res, rn, field_for_columns) ? NULL :
+ PQgetvalue(res, rn, field_for_columns);
+ val1 = NULL;
+
+ if (sort_field_for_columns >= 0 &&
+ !PQgetisnull(res, rn, sort_field_for_columns))
+ val1 = PQgetvalue(res, rn, sort_field_for_columns);
+
+ avlMergeValue(&piv_columns, val, val1);
+
+ if (piv_columns.count > CROSSTABVIEW_MAX_COLUMNS)
+ {
+ psql_error(_("Maximum number of columns (%d) exceeded\n"),
+ CROSSTABVIEW_MAX_COLUMNS);
+ goto error_return;
+ }
+
+ /* vertical */
+ val = PQgetisnull(res, rn, field_for_rows) ? NULL :
+ PQgetvalue(res, rn, field_for_rows);
+
+ avlMergeValue(&piv_rows, val, NULL);
+ }
+
+ /*
+ * Second part: Generate sorted arrays from the AVL trees.
+ */
+
+ num_columns = piv_columns.count;
+ num_rows = piv_rows.count;
+
+ array_columns = (pivot_field *)
+ pg_malloc(sizeof(pivot_field) * num_columns);
+
+ array_rows = (pivot_field *)
+ pg_malloc(sizeof(pivot_field) * num_rows);
+
+ avlCollectFields(&piv_columns, piv_columns.root, array_columns, 0);
+ avlCollectFields(&piv_rows, piv_rows.root, array_rows, 0);
+
+ /*
+ * Third part: optionally, process the ranking data for the horizontal
+ * header
+ */
+ if (sort_field_for_columns >= 0)
+ rankSort(num_columns, array_columns);
+
+ /*
+ * Fourth part: print the crosstab'ed results.
+ */
+ retval = printCrosstab(res,
+ num_columns, array_columns, field_for_columns,
+ num_rows, array_rows, field_for_rows,
+ field_for_data);
+
+error_return:
+ avlFree(&piv_columns, piv_columns.root);
+ avlFree(&piv_rows, piv_rows.root);
+ pg_free(array_columns);
+ pg_free(array_rows);
+ pg_free(colsV);
+ pg_free(colsH);
+ pg_free(colsD);
+
+ return retval;
+}
+
+/*
+ * Output the pivoted resultset with the printTable* functions. Return true
+ * if successful, false otherwise.
+ */
+static bool
+printCrosstab(const PGresult *results,
+ int num_columns, pivot_field *piv_columns, int field_for_columns,
+ int num_rows, pivot_field *piv_rows, int field_for_rows,
+ int field_for_data)
+{
+ printQueryOpt popt = pset.popt;
+ printTableContent cont;
+ int i,
+ rn;
+ char col_align;
+ int *horiz_map;
+ bool retval = false;
+
+ printTableInit(&cont, &popt.topt, popt.title, num_columns + 1, num_rows);
+
+ /* Step 1: set target column names (horizontal header) */
+
+ /* The name of the first column is kept unchanged by the pivoting */
+ printTableAddHeader(&cont,
+ PQfname(results, field_for_rows),
+ false,
+ column_type_alignment(PQftype(results,
+ field_for_rows)));
+
+ /*
+ * To iterate over piv_columns[] by piv_columns[].rank, create a reverse
+ * map associating each piv_columns[].rank to its index in piv_columns.
+ * This avoids an O(N^2) loop later.
+ */
+ horiz_map = (int *) pg_malloc(sizeof(int) * num_columns);
+ for (i = 0; i < num_columns; i++)
+ horiz_map[piv_columns[i].rank] = i;
+
+ /*
+ * The display alignment depends on its PQftype().
+ */
+ col_align = column_type_alignment(PQftype(results, field_for_data));
+
+ for (i = 0; i < num_columns; i++)
+ {
+ char *colname;
+
+ colname = piv_columns[horiz_map[i]].name ?
+ piv_columns[horiz_map[i]].name :
+ (popt.nullPrint ? popt.nullPrint : "");
+
+ printTableAddHeader(&cont, colname, false, col_align);
+ }
+ pg_free(horiz_map);
+
+ /* Step 2: set row names in the first output column (vertical header) */
+ for (i = 0; i < num_rows; i++)
+ {
+ int k = piv_rows[i].rank;
+
+ cont.cells[k * (num_columns + 1)] = piv_rows[i].name ?
+ piv_rows[i].name :
+ (popt.nullPrint ? popt.nullPrint : "");
+ }
+ cont.cellsadded = num_rows * (num_columns + 1);
+
+ /*
+ * Step 3: fill in the content cells.
+ */
+ for (rn = 0; rn < PQntuples(results); rn++)
+ {
+ int row_number;
+ int col_number;
+ pivot_field *p;
+ pivot_field elt;
+
+ /* Find target row */
+ if (!PQgetisnull(results, rn, field_for_rows))
+ elt.name = PQgetvalue(results, rn, field_for_rows);
+ else
+ elt.name = NULL;
+ p = (pivot_field *) bsearch(&elt,
+ piv_rows,
+ num_rows,
+ sizeof(pivot_field),
+ pivotFieldCompare);
+ Assert(p != NULL);
+ row_number = p->rank;
+
+ /* Find target column */
+ if (!PQgetisnull(results, rn, field_for_columns))
+ elt.name = PQgetvalue(results, rn, field_for_columns);
+ else
+ elt.name = NULL;
+
+ p = (pivot_field *) bsearch(&elt,
+ piv_columns,
+ num_columns,
+ sizeof(pivot_field),
+ pivotFieldCompare);
+ Assert(p != NULL);
+ col_number = p->rank;
+
+ /* Place value into cell */
+ if (col_number >= 0 && row_number >= 0)
+ {
+ int idx;
+
+ /* index into the cont.cells array */
+ idx = 1 + col_number + row_number * (num_columns + 1);
+
+ /*
+ * If the cell already contains a value, raise an error.
+ */
+ if (cont.cells[idx] != NULL)
+ {
+ psql_error(_("data cell already contains a value: (row: \"%s\", column: \"%s\")\n"),
+ piv_rows[row_number].name ? piv_rows[row_number].name :
+ popt.nullPrint ? popt.nullPrint : "(null)",
+ piv_columns[col_number].name ? piv_columns[col_number].name :
+ popt.nullPrint ? popt.nullPrint : "(null)");
+ goto error;
+ }
+
+ cont.cells[idx] = !PQgetisnull(results, rn, field_for_data) ?
+ PQgetvalue(results, rn, field_for_data) :
+ (popt.nullPrint ? popt.nullPrint : "");
+ }
+ }
+
+ /*
+ * The non-initialized cells must be set to an empty string for the print
+ * functions
+ */
+ for (i = 0; i < cont.cellsadded; i++)
+ {
+ if (cont.cells[i] == NULL)
+ cont.cells[i] = "";
+ }
+
+ printTable(&cont, pset.queryFout, false, pset.logfile);
+ retval = true;
+
+error:
+ printTableCleanup(&cont);
+
+ return retval;
+}
+
+/*
+ * Parse col1[col2][col3]...
+ * where colN can be:
+ * - a number from 1 to PQnfields(res)
+ * - an unquoted column name matching (case insensitively) one of PQfname(res,...)
+ * - a quoted column name matching (case sensitively) one of PQfname(res,...)
+ * max_columns: 0 if no maximum
+ */
+static int
+parseColumnRefs(char *arg,
+ PGresult *res,
+ int **col_numbers,
+ int max_columns,
+ char separator)
+{
+ char *p = arg;
+ char c;
+ int col_num = -1;
+ int nb_cols = 0;
+ char *field_start = NULL;
+
+ *col_numbers = NULL;
+ while ((c = *p) != '\0')
+ {
+ bool quoted_field = false;
+
+ field_start = p;
+
+ /* first char */
+ if (c == '"')
+ {
+ quoted_field = true;
+ p++;
+ }
+
+ while ((c = *p) != '\0')
+ {
+ if (c == separator && !quoted_field)
+ break;
+ if (c == '"') /* end of field or embedded double quote */
+ {
+ p++;
+ if (*p == '"')
+ {
+ if (quoted_field)
+ {
+ p++;
+ continue;
+ }
+ }
+ else if (quoted_field && *p == separator)
+ break;
+ }
+ if (*p)
+ p += PQmblen(p, pset.encoding);
+ }
+
+ if (p != field_start)
+ {
+ /* look up the column and add its index into *col_numbers */
+ if (max_columns != 0 && nb_cols == max_columns)
+ {
+ psql_error(_("No more than %d column references expected\n"), max_columns);
+ goto errfail;
+ }
+ c = *p;
+ *p = '\0';
+ col_num = indexOfColumn(field_start, res);
+ if (col_num < 0)
+ goto errfail;
+ *p = c;
+ *col_numbers = (int *) pg_realloc(*col_numbers, (1 + nb_cols) * sizeof(int));
+ (*col_numbers)[nb_cols++] = col_num;
+ }
+ else
+ {
+ psql_error(_("Empty column reference\n"));
+ goto errfail;
+ }
+
+ if (*p)
+ p += PQmblen(p, pset.encoding);
+ }
+ return nb_cols;
+
+errfail:
+ pg_free(*col_numbers);
+ *col_numbers = NULL;
+ return -1;
+}
+
+/*
+ * The avl* functions below provide a minimalistic implementation of AVL binary
+ * trees, to efficiently collect the distinct values that will form the horizontal
+ * and vertical headers. It only supports adding new values, no removal or even
+ * search.
+ */
+static void
+avlInit(avl_tree *tree)
+{
+ tree->end = (avl_node *) pg_malloc0(sizeof(avl_node));
+ tree->end->children[0] = tree->end->children[1] = tree->end;
+ tree->count = 0;
+ tree->root = tree->end;
+}
+
+/* Deallocate recursively an AVL tree, starting from node */
+static void
+avlFree(avl_tree *tree, avl_node *node)
+{
+ if (node->children[0] != tree->end)
+ {
+ avlFree(tree, node->children[0]);
+ pg_free(node->children[0]);
+ }
+ if (node->children[1] != tree->end)
+ {
+ avlFree(tree, node->children[1]);
+ pg_free(node->children[1]);
+ }
+ if (node == tree->root)
+ {
+ /* free the root separately as it's not child of anything */
+ if (node != tree->end)
+ pg_free(node);
+ /* free the tree->end struct only once and when all else is freed */
+ pg_free(tree->end);
+ }
+}
+
+/* Set the height to 1 plus the greatest of left and right heights */
+static void
+avlUpdateHeight(avl_node *n)
+{
+ n->height = 1 + (n->children[0]->height > n->children[1]->height ?
+ n->children[0]->height :
+ n->children[1]->height);
+}
+
+/* Rotate a subtree left (dir=0) or right (dir=1). Not recursive */
+static avl_node *
+avlRotate(avl_node **current, int dir)
+{
+ avl_node *before = *current;
+ avl_node *after = (*current)->children[dir];
+
+ *current = after;
+ before->children[dir] = after->children[!dir];
+ avlUpdateHeight(before);
+ after->children[!dir] = before;
+
+ return after;
+}
+
+static int
+avlBalance(avl_node *n)
+{
+ return n->children[0]->height - n->children[1]->height;
+}
+
+/*
+ * After an insertion, possibly rebalance the tree so that the left and right
+ * node heights don't differ by more than 1.
+ * May update *node.
+ */
+static void
+avlAdjustBalance(avl_tree *tree, avl_node **node)
+{
+ avl_node *current = *node;
+ int b = avlBalance(current) / 2;
+
+ if (b != 0)
+ {
+ int dir = (1 - b) / 2;
+
+ if (avlBalance(current->children[dir]) == -b)
+ avlRotate(¤t->children[dir], !dir);
+ current = avlRotate(node, dir);
+ }
+ if (current != tree->end)
+ avlUpdateHeight(current);
+}
+
+/*
+ * Insert a new value/field, starting from *node, reaching the correct position
+ * in the tree by recursion. Possibly rebalance the tree and possibly update
+ * *node. Do nothing if the value is already present in the tree.
+ */
+static void
+avlInsertNode(avl_tree *tree, avl_node **node, pivot_field field)
+{
+ avl_node *current = *node;
+
+ if (current == tree->end)
+ {
+ avl_node *new_node = (avl_node *)
+ pg_malloc(sizeof(avl_node));
+
+ new_node->height = 1;
+ new_node->field = field;
+ new_node->children[0] = new_node->children[1] = tree->end;
+ tree->count++;
+ *node = new_node;
+ }
+ else
+ {
+ int cmp = pivotFieldCompare(&field, ¤t->field);
+
+ if (cmp != 0)
+ {
+ avlInsertNode(tree,
+ cmp > 0 ? ¤t->children[1] : ¤t->children[0],
+ field);
+ avlAdjustBalance(tree, node);
+ }
+ }
+}
+
+/* Insert the value into the AVL tree, if it does not preexist */
+static void
+avlMergeValue(avl_tree *tree, char *name, char *sort_value)
+{
+ pivot_field field;
+
+ field.name = name;
+ field.rank = tree->count;
+ field.sort_value = sort_value;
+ avlInsertNode(tree, &tree->root, field);
+}
+
+/*
+ * Recursively extract node values into the names array, in sorted order with a
+ * left-to-right tree traversal.
+ * Return the next candidate offset to write into the names array.
+ * fields[] must be preallocated to hold tree->count entries
+ */
+static int
+avlCollectFields(avl_tree *tree, avl_node *node, pivot_field *fields, int idx)
+{
+ if (node == tree->end)
+ return idx;
+
+ idx = avlCollectFields(tree, node->children[0], fields, idx);
+ fields[idx] = node->field;
+ return avlCollectFields(tree, node->children[1], fields, idx + 1);
+}
+
+static void
+rankSort(int num_columns, pivot_field *piv_columns)
+{
+ int *hmap; /* [[offset in piv_columns, rank], ...for
+ * every header entry] */
+ int i;
+
+ hmap = (int *) pg_malloc(sizeof(int) * num_columns * 2);
+ for (i = 0; i < num_columns; i++)
+ {
+ char *val = piv_columns[i].sort_value;
+
+ /* ranking information is valid if non null and matches /^-?\d+$/ */
+ if (val &&
+ ((*val == '-' &&
+ strspn(val + 1, "0123456789") == strlen(val + 1)) ||
+ strspn(val, "0123456789") == strlen(val)))
+ {
+ hmap[i * 2] = atoi(val);
+ hmap[i * 2 + 1] = i;
+ }
+ else
+ {
+ /* invalid rank information ignored (equivalent to rank 0) */
+ hmap[i * 2] = 0;
+ hmap[i * 2 + 1] = i;
+ }
+ }
+
+ qsort(hmap, num_columns, sizeof(int) * 2, rankCompare);
+
+ for (i = 0; i < num_columns; i++)
+ {
+ piv_columns[hmap[i * 2 + 1]].rank = i;
+ }
+
+ pg_free(hmap);
+}
+
+/*
+ * Compare a user-supplied argument against a field name obtained by PQfname(),
+ * which is already case-folded.
+ * If arg is not enclosed in double quotes, pg_strcasecmp applies, otherwise
+ * do a case-sensitive comparison with these rules:
+ * - double quotes enclosing 'arg' are filtered out
+ * - double quotes inside 'arg' are expected to be doubled
+ */
+static bool
+fieldNameEquals(const char *arg, const char *fieldname)
+{
+ const char *p = arg;
+ const char *f = fieldname;
+ char c;
+
+ if (*p++ != '"')
+ return !pg_strcasecmp(arg, fieldname);
+
+ while ((c = *p++))
+ {
+ if (c == '"')
+ {
+ if (*p == '"')
+ p++; /* skip second quote and continue */
+ else if (*p == '\0')
+ return (*f == '\0'); /* p is shorter than f, or is
+ * identical */
+ }
+ if (*f == '\0')
+ return false; /* f is shorter than p */
+ if (c != *f) /* found one byte that differs */
+ return false;
+ f++;
+ }
+ return (*f == '\0');
+}
+
+/*
+ * arg can be a number or a column name, possibly quoted (like in an ORDER BY clause)
+ * Returns:
+ * on success, the 0-based index of the column
+ * or -1 if the column number or name is not found in the result's structure,
+ * or if it's ambiguous (arg corresponding to several columns)
+ */
+static int
+indexOfColumn(const char *arg, PGresult *res)
+{
+ int idx;
+
+ if (strspn(arg, "0123456789") == strlen(arg))
+ {
+ /* if arg contains only digits, it's a column number */
+ idx = atoi(arg) - 1;
+ if (idx < 0 || idx >= PQnfields(res))
+ {
+ psql_error(_("Invalid column number: %s\n"), arg);
+ return -1;
+ }
+ }
+ else
+ {
+ int i;
+
+ idx = -1;
+ for (i = 0; i < PQnfields(res); i++)
+ {
+ if (fieldNameEquals(arg, PQfname(res, i)))
+ {
+ if (idx >= 0)
+ {
+ /* if another idx was already found for the same name */
+ psql_error(_("Ambiguous column name: %s\n"), arg);
+ return -1;
+ }
+ idx = i;
+ }
+ }
+ if (idx == -1)
+ {
+ psql_error(_("Invalid column name: %s\n"), arg);
+ return -1;
+ }
+ }
+
+ return idx;
+}
+
+/*
+ * Value comparator for vertical and horizontal headers
+ * used for deduplication only.
+ * - null values are considered equal
+ * - non-null < null
+ * - non-null values are compared with strcmp()
+ */
+static int
+pivotFieldCompare(const void *a, const void *b)
+{
+ pivot_field *pa = (pivot_field *) a;
+ pivot_field *pb = (pivot_field *) b;
+
+ /* test null values */
+ if (!pb->name)
+ return pa->name ? -1 : 0;
+ else if (!pa->name)
+ return 1;
+
+ /* non-null values */
+ return strcmp(((pivot_field *) a)->name,
+ ((pivot_field *) b)->name);
+}
+
+static int
+rankCompare(const void *a, const void *b)
+{
+ return *((int *) a) - *((int *) b);
+}
diff --git a/src/bin/psql/crosstabview.h b/src/bin/psql/crosstabview.h
new file mode 100644
index 00000000000..3cb4d755890
--- /dev/null
+++ b/src/bin/psql/crosstabview.h
@@ -0,0 +1,26 @@
+/*
+ * psql - the PostgreSQL interactive terminal
+ *
+ * Copyright (c) 2000-2016, PostgreSQL Global Development Group
+ *
+ * src/bin/psql/crosstabview.h
+ */
+
+#ifndef CROSSTABVIEW_H
+#define CROSSTABVIEW_H
+
+/*
+ * Limit the number of output columns generated in memory by the crosstabview
+ * algorithm. A new output column is added for each distinct value found in the
+ * column that pivots (to form the horizontal header).
+ * The purpose of this limit is to fail early instead of over-allocating or spending
+ * too much time if the crosstab to generate happens to be unreasonably large
+ * (worst case: a NxN cartesian product with N=number of tuples).
+ * The value of 1600 corresponds to the maximum columns per table in storage,
+ * but it could be as much as INT_MAX theorically.
+ */
+#define CROSSTABVIEW_MAX_COLUMNS 1600
+
+/* prototypes */
+extern bool PrintResultsInCrosstab(PGresult *res);
+#endif /* CROSSTABVIEW_H */
diff --git a/src/bin/psql/help.c b/src/bin/psql/help.c
index eda31e2fb0f..b4021417863 100644
--- a/src/bin/psql/help.c
+++ b/src/bin/psql/help.c
@@ -177,6 +177,7 @@ slashUsage(unsigned short int pager)
fprintf(output, _(" \\gexec execute query, then execute each value in its result\n"));
fprintf(output, _(" \\gset [PREFIX] execute query and store results in psql variables\n"));
fprintf(output, _(" \\q quit psql\n"));
+ fprintf(output, _(" \\crosstabview [COLUMNS] execute query and display results in crosstab\n"));
fprintf(output, _(" \\watch [SEC] execute query every SEC seconds\n"));
fprintf(output, "\n");
diff --git a/src/bin/psql/settings.h b/src/bin/psql/settings.h
index c69f6ba1ec4..643ff8cd5bb 100644
--- a/src/bin/psql/settings.h
+++ b/src/bin/psql/settings.h
@@ -93,6 +93,10 @@ typedef struct _psqlSettings
char *gfname; /* one-shot file output argument for \g */
char *gset_prefix; /* one-shot prefix argument for \gset */
bool gexec_flag; /* one-shot flag to execute query's results */
+ bool crosstab_flag; /* one-shot request to crosstab results */
+ char *ctv_col_V; /* \crosstabview 1st argument */
+ char *ctv_col_H; /* \crosstabview 2nd argument */
+ char *ctv_col_D; /* \crosstabview 3nd argument */
bool notty; /* stdin or stdout is not a tty (as determined
* on startup) */
diff --git a/src/bin/psql/tab-complete.c b/src/bin/psql/tab-complete.c
index 6d092711e83..a62ffe61e05 100644
--- a/src/bin/psql/tab-complete.c
+++ b/src/bin/psql/tab-complete.c
@@ -1274,7 +1274,8 @@ psql_completion(const char *text, int start, int end)
/* psql's backslash commands. */
static const char *const backslash_commands[] = {
- "\\a", "\\connect", "\\conninfo", "\\C", "\\cd", "\\copy", "\\copyright",
+ "\\a", "\\connect", "\\conninfo", "\\C", "\\cd", "\\copy",
+ "\\copyright", "\\crosstabview",
"\\d", "\\da", "\\db", "\\dc", "\\dC", "\\dd", "\\ddp", "\\dD",
"\\des", "\\det", "\\deu", "\\dew", "\\dE", "\\df",
"\\dF", "\\dFd", "\\dFp", "\\dFt", "\\dg", "\\di", "\\dl", "\\dL",
diff --git a/src/fe_utils/print.c b/src/fe_utils/print.c
index 30efd3fdc62..1ec74f17907 100644
--- a/src/fe_utils/print.c
+++ b/src/fe_utils/print.c
@@ -3295,30 +3295,9 @@ printQuery(const PGresult *result, const printQueryOpt *opt,
for (i = 0; i < cont.ncolumns; i++)
{
- char align;
- Oid ftype = PQftype(result, i);
-
- switch (ftype)
- {
- case INT2OID:
- case INT4OID:
- case INT8OID:
- case FLOAT4OID:
- case FLOAT8OID:
- case NUMERICOID:
- case OIDOID:
- case XIDOID:
- case CIDOID:
- case CASHOID:
- align = 'r';
- break;
- default:
- align = 'l';
- break;
- }
-
printTableAddHeader(&cont, PQfname(result, i),
- opt->translate_header, align);
+ opt->translate_header,
+ column_type_alignment(PQftype(result, i)));
}
/* set cells */
@@ -3360,6 +3339,31 @@ printQuery(const PGresult *result, const printQueryOpt *opt,
printTableCleanup(&cont);
}
+char
+column_type_alignment(Oid ftype)
+{
+ char align;
+
+ switch (ftype)
+ {
+ case INT2OID:
+ case INT4OID:
+ case INT8OID:
+ case FLOAT4OID:
+ case FLOAT8OID:
+ case NUMERICOID:
+ case OIDOID:
+ case XIDOID:
+ case CIDOID:
+ case CASHOID:
+ align = 'r';
+ break;
+ default:
+ align = 'l';
+ break;
+ }
+ return align;
+}
void
setDecimalLocale(void)
diff --git a/src/include/fe_utils/print.h b/src/include/fe_utils/print.h
index ff902370f32..18aee93ecd5 100644
--- a/src/include/fe_utils/print.h
+++ b/src/include/fe_utils/print.h
@@ -206,6 +206,8 @@ extern void printTable(const printTableContent *cont,
extern void printQuery(const PGresult *result, const printQueryOpt *opt,
FILE *fout, bool is_pager, FILE *flog);
+extern char column_type_alignment(Oid);
+
extern void setDecimalLocale(void);
extern const printTextFormat *get_line_style(const printTableOpt *opt);
extern void refresh_utf8format(const printTableOpt *opt);
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index edcc414630c..9e98e9d62fd 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -2476,6 +2476,7 @@ execute q;
+------------------+-------------------+
deallocate q;
+\pset linestyle ascii
prepare q as select ' | = | lkjsafi\\/ /oeu rio)(!@&*#)*(!&@*) \ (&' as " | -- | 012345678 9abc def!*@#&!@(*&*~~_+-=\ \", '11' as "0123456789", 11 as int from generate_series(1,10) as n;
\pset format asciidoc
\pset expanded off
@@ -2682,6 +2683,9 @@ execute q;
l|11
|====
deallocate q;
+\pset format aligned
+\pset expanded off
+\pset border 1
-- SHOW_CONTEXT
\set SHOW_CONTEXT never
do $$
@@ -2710,3 +2714,188 @@ NOTICE: foo
CONTEXT: PL/pgSQL function inline_code_block line 3 at RAISE
ERROR: bar
CONTEXT: PL/pgSQL function inline_code_block line 4 at RAISE
+--
+-- \crosstabview
+--
+CREATE TABLE ctv_data (v, h, c, i, d) AS
+VALUES
+ ('v1','h2','foo', 3, '2015-04-01'::date),
+ ('v2','h1','bar', 3, '2015-01-02'),
+ ('v1','h0','baz', NULL, '2015-07-12'),
+ ('v0','h4','qux', 4, '2015-07-15'),
+ ('v0','h4','dbl', -3, '2014-12-15'),
+ ('v0',NULL,'qux', 5, '2014-07-15'),
+ ('v1','h2','quux',7, '2015-04-04');
+-- running \crosstabview after query uses query in buffer
+SELECT v, EXTRACT(year FROM d), count(*)
+ FROM ctv_data
+ GROUP BY 1, 2
+ ORDER BY 1, 2;
+ v | date_part | count
+----+-----------+-------
+ v0 | 2014 | 2
+ v0 | 2015 | 1
+ v1 | 2015 | 3
+ v2 | 2015 | 1
+(4 rows)
+
+-- basic usage with 3 columns
+ \crosstabview
+ v | 2014 | 2015
+----+------+------
+ v0 | 2 | 1
+ v1 | | 3
+ v2 | | 1
+(3 rows)
+
+-- ordered months in horizontal header, quoted column name
+SELECT v, to_char(d, 'Mon') AS "month name", EXTRACT(month FROM d) AS num,
+ count(*) FROM ctv_data GROUP BY 1,2,3 ORDER BY 1
+ \crosstabview v "month name":num 4
+ v | Jan | Apr | Jul | Dec
+----+-----+-----+-----+-----
+ v0 | | | 2 | 1
+ v1 | | 2 | 1 |
+ v2 | 1 | | |
+(3 rows)
+
+-- ordered months in vertical header, ordered years in horizontal header
+SELECT EXTRACT(year FROM d) AS year, to_char(d,'Mon') AS "month name",
+ EXTRACT(month FROM d) AS month,
+ format('sum=%s avg=%s', sum(i), avg(i)::numeric(2,1))
+ FROM ctv_data
+ GROUP BY EXTRACT(year FROM d), to_char(d,'Mon'), EXTRACT(month FROM d)
+ORDER BY month
+\crosstabview "month name" year:year format
+ month name | 2014 | 2015
+------------+-----------------+----------------
+ Jan | | sum=3 avg=3.0
+ Apr | | sum=10 avg=5.0
+ Jul | sum=5 avg=5.0 | sum=4 avg=4.0
+ Dec | sum=-3 avg=-3.0 |
+(4 rows)
+
+-- combine contents vertically into the same cell (V/H duplicates)
+SELECT v, h, string_agg(c, E'\n') FROM ctv_data GROUP BY v, h ORDER BY 1,2,3
+ \crosstabview 1 2 3
+ v | h4 | | h0 | h2 | h1
+----+-----+-----+-----+------+-----
+ v0 | qux+| qux | | |
+ | dbl | | | |
+ v1 | | | baz | foo +|
+ | | | | quux |
+ v2 | | | | | bar
+(3 rows)
+
+-- horizontal ASC order from window function
+SELECT v,h, string_agg(c, E'\n') AS c, row_number() OVER(ORDER BY h) AS r
+FROM ctv_data GROUP BY v, h ORDER BY 1,3,2
+ \crosstabview v h:r c
+ v | h0 | h1 | h2 | h4 |
+----+-----+-----+------+-----+-----
+ v0 | | | | qux+| qux
+ | | | | dbl |
+ v1 | baz | | foo +| |
+ | | | quux | |
+ v2 | | bar | | |
+(3 rows)
+
+-- horizontal DESC order from window function
+SELECT v, h, string_agg(c, E'\n') AS c, row_number() OVER(ORDER BY h DESC) AS r
+FROM ctv_data GROUP BY v, h ORDER BY 1,3,2
+ \crosstabview v h:r c
+ v | | h4 | h2 | h1 | h0
+----+-----+-----+------+-----+-----
+ v0 | qux | qux+| | |
+ | | dbl | | |
+ v1 | | | foo +| | baz
+ | | | quux | |
+ v2 | | | | bar |
+(3 rows)
+
+-- horizontal ASC order from window function, NULLs pushed rightmost
+SELECT v,h, string_agg(c, E'\n') AS c, row_number() OVER(ORDER BY h NULLS LAST) AS r
+FROM ctv_data GROUP BY v, h ORDER BY 1,3,2
+ \crosstabview v h:r c
+ v | h0 | h1 | h2 | h4 |
+----+-----+-----+------+-----+-----
+ v0 | | | | qux+| qux
+ | | | | dbl |
+ v1 | baz | | foo +| |
+ | | | quux | |
+ v2 | | bar | | |
+(3 rows)
+
+-- only null, no column name, 2 columns: error
+SELECT null,null \crosstabview
+The query must return at least two columns to be shown in crosstab
+-- only null, no column name, 3 columns: works
+SELECT null,null,null \crosstabview
+ ?column? |
+----------+--
+ |
+(1 row)
+
+-- null display
+\pset null '#null#'
+SELECT v,h, string_agg(i::text, E'\n') AS i FROM ctv_data
+GROUP BY v, h ORDER BY h,v
+ \crosstabview v h i
+ v | h0 | h1 | h2 | h4 | #null#
+----+--------+----+----+----+--------
+ v1 | #null# | | 3 +| |
+ | | | 7 | |
+ v2 | | 3 | | |
+ v0 | | | | 4 +| 5
+ | | | | -3 |
+(3 rows)
+
+\pset null ''
+-- refer to columns by position
+SELECT v,h,string_agg(i::text, E'\n'), string_agg(c, E'\n')
+FROM ctv_data GROUP BY v, h ORDER BY h,v
+ \crosstabview 2 1 4
+ h | v1 | v2 | v0
+----+------+-----+-----
+ h0 | baz | |
+ h1 | | bar |
+ h2 | foo +| |
+ | quux | |
+ h4 | | | qux+
+ | | | dbl
+ | | | qux
+(5 rows)
+
+-- refer to columns by positions and names mixed
+SELECT v,h, string_agg(i::text, E'\n') AS i, string_agg(c, E'\n') AS c
+FROM ctv_data GROUP BY v, h ORDER BY h,v
+ \crosstabview 1 "h" 4
+ v | h0 | h1 | h2 | h4 |
+----+-----+-----+------+-----+-----
+ v1 | baz | | foo +| |
+ | | | quux | |
+ v2 | | bar | | |
+ v0 | | | | qux+| qux
+ | | | | dbl |
+(3 rows)
+
+-- error: bad column name
+SELECT v,h,c,i FROM ctv_data
+ \crosstabview v h j
+Invalid column name: j
+-- error: bad column number
+SELECT v,h,i,c FROM ctv_data
+ \crosstabview 2 1 5
+Invalid column number: 5
+-- error: same H and V columns
+SELECT v,h,i,c FROM ctv_data
+ \crosstabview 2 h 4
+The same column cannot be used for both vertical and horizontal headers
+-- error: too many columns
+SELECT a,a,1 FROM generate_series(1,3000) AS a
+ \crosstabview
+Maximum number of columns (1600) exceeded
+-- error: only one column
+SELECT 1 \crosstabview
+The query must return at least two columns to be shown in crosstab
+DROP TABLE ctv_data;
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index c5b36649491..2e332afc963 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -326,6 +326,8 @@ execute q;
deallocate q;
+\pset linestyle ascii
+
prepare q as select ' | = | lkjsafi\\/ /oeu rio)(!@&*#)*(!&@*) \ (&' as " | -- | 012345678 9abc def!*@#&!@(*&*~~_+-=\ \", '11' as "0123456789", 11 as int from generate_series(1,10) as n;
\pset format asciidoc
@@ -351,6 +353,10 @@ execute q;
deallocate q;
+\pset format aligned
+\pset expanded off
+\pset border 1
+
-- SHOW_CONTEXT
\set SHOW_CONTEXT never
@@ -373,3 +379,102 @@ begin
raise notice 'foo';
raise exception 'bar';
end $$;
+
+--
+-- \crosstabview
+--
+
+CREATE TABLE ctv_data (v, h, c, i, d) AS
+VALUES
+ ('v1','h2','foo', 3, '2015-04-01'::date),
+ ('v2','h1','bar', 3, '2015-01-02'),
+ ('v1','h0','baz', NULL, '2015-07-12'),
+ ('v0','h4','qux', 4, '2015-07-15'),
+ ('v0','h4','dbl', -3, '2014-12-15'),
+ ('v0',NULL,'qux', 5, '2014-07-15'),
+ ('v1','h2','quux',7, '2015-04-04');
+
+-- running \crosstabview after query uses query in buffer
+SELECT v, EXTRACT(year FROM d), count(*)
+ FROM ctv_data
+ GROUP BY 1, 2
+ ORDER BY 1, 2;
+-- basic usage with 3 columns
+ \crosstabview
+
+-- ordered months in horizontal header, quoted column name
+SELECT v, to_char(d, 'Mon') AS "month name", EXTRACT(month FROM d) AS num,
+ count(*) FROM ctv_data GROUP BY 1,2,3 ORDER BY 1
+ \crosstabview v "month name":num 4
+
+-- ordered months in vertical header, ordered years in horizontal header
+SELECT EXTRACT(year FROM d) AS year, to_char(d,'Mon') AS "month name",
+ EXTRACT(month FROM d) AS month,
+ format('sum=%s avg=%s', sum(i), avg(i)::numeric(2,1))
+ FROM ctv_data
+ GROUP BY EXTRACT(year FROM d), to_char(d,'Mon'), EXTRACT(month FROM d)
+ORDER BY month
+\crosstabview "month name" year:year format
+
+-- combine contents vertically into the same cell (V/H duplicates)
+SELECT v, h, string_agg(c, E'\n') FROM ctv_data GROUP BY v, h ORDER BY 1,2,3
+ \crosstabview 1 2 3
+
+-- horizontal ASC order from window function
+SELECT v,h, string_agg(c, E'\n') AS c, row_number() OVER(ORDER BY h) AS r
+FROM ctv_data GROUP BY v, h ORDER BY 1,3,2
+ \crosstabview v h:r c
+
+-- horizontal DESC order from window function
+SELECT v, h, string_agg(c, E'\n') AS c, row_number() OVER(ORDER BY h DESC) AS r
+FROM ctv_data GROUP BY v, h ORDER BY 1,3,2
+ \crosstabview v h:r c
+
+-- horizontal ASC order from window function, NULLs pushed rightmost
+SELECT v,h, string_agg(c, E'\n') AS c, row_number() OVER(ORDER BY h NULLS LAST) AS r
+FROM ctv_data GROUP BY v, h ORDER BY 1,3,2
+ \crosstabview v h:r c
+
+-- only null, no column name, 2 columns: error
+SELECT null,null \crosstabview
+
+-- only null, no column name, 3 columns: works
+SELECT null,null,null \crosstabview
+
+-- null display
+\pset null '#null#'
+SELECT v,h, string_agg(i::text, E'\n') AS i FROM ctv_data
+GROUP BY v, h ORDER BY h,v
+ \crosstabview v h i
+\pset null ''
+
+-- refer to columns by position
+SELECT v,h,string_agg(i::text, E'\n'), string_agg(c, E'\n')
+FROM ctv_data GROUP BY v, h ORDER BY h,v
+ \crosstabview 2 1 4
+
+-- refer to columns by positions and names mixed
+SELECT v,h, string_agg(i::text, E'\n') AS i, string_agg(c, E'\n') AS c
+FROM ctv_data GROUP BY v, h ORDER BY h,v
+ \crosstabview 1 "h" 4
+
+-- error: bad column name
+SELECT v,h,c,i FROM ctv_data
+ \crosstabview v h j
+
+-- error: bad column number
+SELECT v,h,i,c FROM ctv_data
+ \crosstabview 2 1 5
+
+-- error: same H and V columns
+SELECT v,h,i,c FROM ctv_data
+ \crosstabview 2 h 4
+
+-- error: too many columns
+SELECT a,a,1 FROM generate_series(1,3000) AS a
+ \crosstabview
+
+-- error: only one column
+SELECT 1 \crosstabview
+
+DROP TABLE ctv_data;