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Document get_call_result_type() and friends; mark TypeGetTupleDesc()
and RelationNameGetTupleDesc() as deprecated; remove uses of the latter in the contrib library. Along the way, clean up crosstab() code and documentation a little.
This commit is contained in:
Tom Lane
@ -57,11 +57,16 @@ Installation:
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but you can create additional crosstab functions per the instructions
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in the documentation below.
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crosstab(text sql, N int)
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crosstab(text sql)
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- returns a set of row_name plus N category value columns
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- requires anonymous composite type syntax in the FROM clause. See
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the instructions in the documentation below.
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crosstab(text sql, N int)
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- obsolete version of crosstab()
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- the argument N is now ignored, since the number of value columns
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is always determined by the calling query
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connectby(text relname, text keyid_fld, text parent_keyid_fld
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[, text orderby_fld], text start_with, int max_depth
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[, text branch_delim])
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@ -133,7 +138,7 @@ Inputs
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A SQL statement which produces the source set of data. The SQL statement
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must return one row_name column, one category column, and one value
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column.
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column. row_name and value must be of type text.
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e.g. provided sql must produce a set something like:
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@ -152,15 +157,15 @@ Outputs
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Returns setof tablefunc_crosstab_N, which is defined by:
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CREATE VIEW tablefunc_crosstab_N AS
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SELECT
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''::TEXT AS row_name,
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''::TEXT AS category_1,
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''::TEXT AS category_2,
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CREATE TYPE tablefunc_crosstab_N AS (
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row_name TEXT,
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category_1 TEXT,
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category_2 TEXT,
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.
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.
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.
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''::TEXT AS category_N;
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category_N TEXT
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);
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for the default installed functions, where N is 2, 3, or 4.
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@ -188,31 +193,9 @@ Notes
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6. The installed defaults are for illustration purposes. You
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can create your own return types and functions based on the
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crosstab() function of the installed library.
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crosstab() function of the installed library. See below for
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details.
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The return type must have a first column that matches the data
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type of the sql set used as its source. The subsequent category
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columns must have the same data type as the value column of the
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sql result set.
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Create a VIEW to define your return type, similar to the VIEWS
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in the provided installation script. Then define a unique function
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name accepting one text parameter and returning setof your_view_name.
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For example, if your source data produces row_names that are TEXT,
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and values that are FLOAT8, and you want 5 category columns:
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CREATE VIEW my_crosstab_float8_5_cols AS
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SELECT
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''::TEXT AS row_name,
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0::FLOAT8 AS category_1,
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0::FLOAT8 AS category_2,
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0::FLOAT8 AS category_3,
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0::FLOAT8 AS category_4,
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0::FLOAT8 AS category_5;
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CREATE OR REPLACE FUNCTION crosstab_float8_5_cols(text)
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RETURNS setof my_crosstab_float8_5_cols
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AS '$libdir/tablefunc','crosstab' LANGUAGE 'c' STABLE STRICT;
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Example usage
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@ -241,11 +224,12 @@ select * from crosstab3(
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==================================================================
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Name
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crosstab(text, int) - returns a set of row_name
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plus N category value columns
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crosstab(text) - returns a set of row_names plus category value columns
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Synopsis
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crosstab(text sql)
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crosstab(text sql, int N)
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Inputs
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@ -271,15 +255,16 @@ Inputs
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N
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number of category value columns
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Obsolete argument; ignored if supplied (formerly this had to match
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the number of category columns determined by the calling query)
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Outputs
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Returns setof record, which must defined with a column definition
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Returns setof record, which must be defined with a column definition
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in the FROM clause of the SELECT statement, e.g.:
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SELECT *
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FROM crosstab(sql, 2) AS ct(row_name text, category_1 text, category_2 text);
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FROM crosstab(sql) AS ct(row_name text, category_1 text, category_2 text);
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the example crosstab function produces a set something like:
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<== values columns ==>
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@ -292,9 +277,12 @@ Notes
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1. The sql result must be ordered by 1,2.
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2. The number of values columns is determined at run-time. The
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column definition provided in the FROM clause must provide for
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N + 1 columns of the proper data types.
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2. The number of values columns is determined by the column definition
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provided in the FROM clause. The FROM clause must define one
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row_name column (of the same datatype as the first result column
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of the sql query) followed by N category columns (of the same
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datatype as the third result column of the sql query). You can
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set up as many category columns as you wish.
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3. Missing values (i.e. not enough adjacent rows of same row_name to
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fill the number of result values columns) are filled in with nulls.
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@ -304,6 +292,44 @@ Notes
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5. Rows with all nulls in the values columns are skipped.
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6. You can avoid always having to write out a FROM clause that defines the
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output columns by setting up a custom crosstab function that has
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the desired output row type wired into its definition.
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There are two ways you can set up a custom crosstab function:
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A. Create a composite type to define your return type, similar to the
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examples in the installation script. Then define a unique function
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name accepting one text parameter and returning setof your_type_name.
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For example, if your source data produces row_names that are TEXT,
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and values that are FLOAT8, and you want 5 category columns:
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CREATE TYPE my_crosstab_float8_5_cols AS (
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row_name TEXT,
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category_1 FLOAT8,
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category_2 FLOAT8,
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category_3 FLOAT8,
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category_4 FLOAT8,
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category_5 FLOAT8
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);
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CREATE OR REPLACE FUNCTION crosstab_float8_5_cols(text)
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RETURNS setof my_crosstab_float8_5_cols
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AS '$libdir/tablefunc','crosstab' LANGUAGE 'c' STABLE STRICT;
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B. Use OUT parameters to define the return type implicitly.
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The same example could also be done this way:
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CREATE OR REPLACE FUNCTION crosstab_float8_5_cols(IN text,
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OUT row_name TEXT,
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OUT category_1 FLOAT8,
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OUT category_2 FLOAT8,
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OUT category_3 FLOAT8,
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OUT category_4 FLOAT8,
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OUT category_5 FLOAT8)
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RETURNS setof record
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AS '$libdir/tablefunc','crosstab' LANGUAGE 'c' STABLE STRICT;
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Example usage
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@ -418,6 +444,10 @@ Notes
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5. Rows with a null row_name column are skipped.
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6. You can create predefined functions to avoid having to write out
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the result column names/types in each query. See the examples
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for crosstab(text).
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Example usage
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@ -102,27 +102,40 @@ SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = '
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test4 | val4 | val5 | val6 |
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(2 rows)
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 2) AS c(rowid text, att1 text, att2 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text);
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rowid | att1 | att2
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-------+------+------
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test1 | val1 | val2
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test2 | val5 | val6
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(2 rows)
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 3) AS c(rowid text, att1 text, att2 text, att3 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text);
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rowid | att1 | att2 | att3
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-------+------+------+------
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test1 | val1 | val2 | val3
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test2 | val5 | val6 | val7
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(2 rows)
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 4) AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
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rowid | att1 | att2 | att3 | att4
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-------+------+------+------+------
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test1 | val1 | val2 | val3 | val4
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test2 | val5 | val6 | val7 | val8
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(2 rows)
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-- check it works with OUT parameters, too
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CREATE FUNCTION crosstab_out(text,
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OUT rowid text, OUT att1 text, OUT att2 text, OUT att3 text)
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RETURNS setof record
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AS '$libdir/tablefunc','crosstab'
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LANGUAGE 'C' STABLE STRICT;
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SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
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rowid | att1 | att2 | att3
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-------+------+------+------
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test1 | val1 | val2 | val3
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test2 | val5 | val6 | val7
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(2 rows)
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--
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-- hash based crosstab
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--
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@ -211,6 +224,40 @@ AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_start
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-------+-------+-------------+-------------+----------------+-------
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(0 rows)
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-- check it works with a named result rowtype
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create type my_crosstab_result as (
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rowid text, rowdt timestamp,
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temperature int4, test_result text, test_startdate timestamp, volts float8);
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CREATE FUNCTION crosstab_named(text, text)
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RETURNS setof my_crosstab_result
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AS '$libdir/tablefunc','crosstab_hash'
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LANGUAGE 'C' STABLE STRICT;
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SELECT * FROM crosstab_named(
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'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
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'SELECT DISTINCT attribute FROM cth ORDER BY 1');
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rowid | rowdt | temperature | test_result | test_startdate | volts
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-------+--------------------------+-------------+-------------+--------------------------+--------
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test1 | Sat Mar 01 00:00:00 2003 | 42 | PASS | | 2.6987
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test2 | Sun Mar 02 00:00:00 2003 | 53 | FAIL | Sat Mar 01 00:00:00 2003 | 3.1234
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(2 rows)
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-- check it works with OUT parameters
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CREATE FUNCTION crosstab_out(text, text,
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OUT rowid text, OUT rowdt timestamp,
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OUT temperature int4, OUT test_result text,
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OUT test_startdate timestamp, OUT volts float8)
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RETURNS setof record
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AS '$libdir/tablefunc','crosstab_hash'
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LANGUAGE 'C' STABLE STRICT;
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SELECT * FROM crosstab_out(
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'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
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'SELECT DISTINCT attribute FROM cth ORDER BY 1');
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rowid | rowdt | temperature | test_result | test_startdate | volts
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-------+--------------------------+-------------+-------------+--------------------------+--------
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test1 | Sat Mar 01 00:00:00 2003 | 42 | PASS | | 2.6987
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test2 | Sun Mar 02 00:00:00 2003 | 53 | FAIL | Sat Mar 01 00:00:00 2003 | 3.1234
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(2 rows)
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--
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-- connectby
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--
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@ -34,9 +34,19 @@ SELECT * FROM crosstab2('SELECT rowid, attribute, val FROM ct where rowclass = '
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SELECT * FROM crosstab3('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
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SELECT * FROM crosstab4('SELECT rowid, attribute, val FROM ct where rowclass = ''group2'' ORDER BY 1,2;');
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 2) AS c(rowid text, att1 text, att2 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 3) AS c(rowid text, att1 text, att2 text, att3 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;', 4) AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text);
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SELECT * FROM crosstab('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;') AS c(rowid text, att1 text, att2 text, att3 text, att4 text);
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-- check it works with OUT parameters, too
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CREATE FUNCTION crosstab_out(text,
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OUT rowid text, OUT att1 text, OUT att2 text, OUT att3 text)
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RETURNS setof record
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AS '$libdir/tablefunc','crosstab'
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LANGUAGE 'C' STABLE STRICT;
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SELECT * FROM crosstab_out('SELECT rowid, attribute, val FROM ct where rowclass = ''group1'' ORDER BY 1,2;');
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--
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-- hash based crosstab
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@ -100,6 +110,35 @@ SELECT * FROM crosstab(
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'SELECT DISTINCT attribute FROM cth WHERE false ORDER BY 1')
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AS c(rowid text, rowdt timestamp, temperature text, test_result text, test_startdate text, volts text);
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-- check it works with a named result rowtype
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create type my_crosstab_result as (
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rowid text, rowdt timestamp,
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temperature int4, test_result text, test_startdate timestamp, volts float8);
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CREATE FUNCTION crosstab_named(text, text)
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RETURNS setof my_crosstab_result
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AS '$libdir/tablefunc','crosstab_hash'
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LANGUAGE 'C' STABLE STRICT;
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SELECT * FROM crosstab_named(
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'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
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'SELECT DISTINCT attribute FROM cth ORDER BY 1');
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-- check it works with OUT parameters
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CREATE FUNCTION crosstab_out(text, text,
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OUT rowid text, OUT rowdt timestamp,
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OUT temperature int4, OUT test_result text,
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OUT test_startdate timestamp, OUT volts float8)
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RETURNS setof record
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AS '$libdir/tablefunc','crosstab_hash'
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LANGUAGE 'C' STABLE STRICT;
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SELECT * FROM crosstab_out(
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'SELECT rowid, rowdt, attribute, val FROM cth ORDER BY 1',
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'SELECT DISTINCT attribute FROM cth ORDER BY 1');
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--
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-- connectby
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--
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@ -51,8 +51,6 @@ static void validateConnectbyTupleDesc(TupleDesc tupdesc, bool show_branch, bool
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static bool compatCrosstabTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
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static bool compatConnectbyTupleDescs(TupleDesc tupdesc1, TupleDesc tupdesc2);
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static void get_normal_pair(float8 *x1, float8 *x2);
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static TupleDesc make_crosstab_tupledesc(TupleDesc spi_tupdesc,
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int num_categories);
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static Tuplestorestate *connectby(char *relname,
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char *key_fld,
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char *parent_key_fld,
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@ -332,12 +330,14 @@ get_normal_pair(float8 *x1, float8 *x2)
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* NOTES:
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* 1. SQL result must be ordered by 1,2.
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* 2. The number of values columns depends on the tuple description
|
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* of the function's declared return type.
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* 2. Missing values (i.e. not enough adjacent rows of same rowid to
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* of the function's declared return type. The return type's columns
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* must match the datatypes of the SQL query's result. The datatype
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* of the category column can be anything, however.
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* 3. Missing values (i.e. not enough adjacent rows of same rowid to
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* fill the number of result values columns) are filled in with nulls.
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* 3. Extra values (i.e. too many adjacent rows of same rowid to fill
|
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* 4. Extra values (i.e. too many adjacent rows of same rowid to fill
|
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* the number of result values columns) are skipped.
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* 4. Rows with all nulls in the values columns are skipped.
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* 5. Rows with all nulls in the values columns are skipped.
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*/
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PG_FUNCTION_INFO_V1(crosstab);
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Datum
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@ -360,10 +360,7 @@ crosstab(PG_FUNCTION_ARGS)
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if (SRF_IS_FIRSTCALL())
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{
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char *sql = GET_STR(PG_GETARG_TEXT_P(0));
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Oid funcid = fcinfo->flinfo->fn_oid;
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Oid functypeid;
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char functyptype;
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TupleDesc tupdesc = NULL;
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TupleDesc tupdesc;
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int ret;
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int proc;
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@ -391,20 +388,23 @@ crosstab(PG_FUNCTION_ARGS)
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spi_tuptable = SPI_tuptable;
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spi_tupdesc = spi_tuptable->tupdesc;
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/*
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/*----------
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* The provided SQL query must always return three columns.
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*
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* 1. rowname the label or identifier for each row in the final
|
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* result 2. category the label or identifier for each column
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* in the final result 3. values the value for each column
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* in the final result
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* 1. rowname
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* the label or identifier for each row in the final result
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* 2. category
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* the label or identifier for each column in the final result
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* 3. values
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* the value for each column in the final result
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*----------
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*/
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if (spi_tupdesc->natts != 3)
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ereport(ERROR,
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(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
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errmsg("invalid source data SQL statement"),
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errdetail("The provided SQL must return 3 " \
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" columns; rowid, category, and values.")));
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errdetail("The provided SQL must return 3 "
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"columns: rowid, category, and values.")));
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}
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else
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{
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@ -416,39 +416,31 @@ crosstab(PG_FUNCTION_ARGS)
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/* SPI switches context on us, so reset it */
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MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
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/* get the typeid that represents our return type */
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functypeid = get_func_rettype(funcid);
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/* check typtype to see if we have a predetermined return type */
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functyptype = get_typtype(functypeid);
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||||
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if (functyptype == 'c')
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/* get a tuple descriptor for our result type */
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switch (get_call_result_type(fcinfo, NULL, &tupdesc))
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||||
{
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||||
/* Build a tuple description for a named composite type */
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||||
tupdesc = TypeGetTupleDesc(functypeid, NIL);
|
||||
}
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||||
else if (functypeid == RECORDOID)
|
||||
{
|
||||
if (fcinfo->nargs != 2)
|
||||
case TYPEFUNC_COMPOSITE:
|
||||
/* success */
|
||||
break;
|
||||
case TYPEFUNC_RECORD:
|
||||
/* failed to determine actual type of RECORD */
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_SYNTAX_ERROR),
|
||||
errmsg("wrong number of arguments")));
|
||||
else
|
||||
{
|
||||
int num_categories = PG_GETARG_INT32(1);
|
||||
|
||||
tupdesc = make_crosstab_tupledesc(spi_tupdesc, num_categories);
|
||||
}
|
||||
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
|
||||
errmsg("function returning record called in context "
|
||||
"that cannot accept type record")));
|
||||
break;
|
||||
default:
|
||||
/* result type isn't composite */
|
||||
elog(ERROR, "return type must be a row type");
|
||||
break;
|
||||
}
|
||||
else
|
||||
ereport(ERROR,
|
||||
(errcode(ERRCODE_SYNTAX_ERROR),
|
||||
errmsg("return type must be a row type")));
|
||||
|
||||
/* make sure we have a persistent copy of the tupdesc */
|
||||
tupdesc = CreateTupleDescCopy(tupdesc);
|
||||
|
||||
/*
|
||||
* Check that return tupdesc is compatible with the one we got
|
||||
* from ret_relname, at least based on number and type of
|
||||
* attributes
|
||||
* Check that return tupdesc is compatible with the data we got
|
||||
* from SPI, at least based on number and type of attributes
|
||||
*/
|
||||
if (!compatCrosstabTupleDescs(tupdesc, spi_tupdesc))
|
||||
ereport(ERROR,
|
||||
@ -679,8 +671,8 @@ crosstab(PG_FUNCTION_ARGS)
|
||||
* 1. SQL result must be ordered by 1.
|
||||
* 2. The number of values columns depends on the tuple description
|
||||
* of the function's declared return type.
|
||||
* 2. Missing values (i.e. missing category) are filled in with nulls.
|
||||
* 3. Extra values (i.e. not in category results) are skipped.
|
||||
* 3. Missing values (i.e. missing category) are filled in with nulls.
|
||||
* 4. Extra values (i.e. not in category results) are skipped.
|
||||
*/
|
||||
PG_FUNCTION_INFO_V1(crosstab_hash);
|
||||
Datum
|
||||
@ -1628,52 +1620,6 @@ compatCrosstabTupleDescs(TupleDesc ret_tupdesc, TupleDesc sql_tupdesc)
|
||||
return true;
|
||||
}
|
||||
|
||||
static TupleDesc
|
||||
make_crosstab_tupledesc(TupleDesc spi_tupdesc, int num_categories)
|
||||
{
|
||||
Form_pg_attribute sql_attr;
|
||||
Oid sql_atttypid;
|
||||
TupleDesc tupdesc;
|
||||
int natts;
|
||||
AttrNumber attnum;
|
||||
char attname[NAMEDATALEN];
|
||||
int i;
|
||||
|
||||
/*
|
||||
* We need to build a tuple description with one column for the
|
||||
* rowname, and num_categories columns for the values. Each must be of
|
||||
* the same type as the corresponding spi result input column.
|
||||
*/
|
||||
natts = num_categories + 1;
|
||||
tupdesc = CreateTemplateTupleDesc(natts, false);
|
||||
|
||||
/* first the rowname column */
|
||||
attnum = 1;
|
||||
|
||||
sql_attr = spi_tupdesc->attrs[0];
|
||||
sql_atttypid = sql_attr->atttypid;
|
||||
|
||||
strcpy(attname, "rowname");
|
||||
|
||||
TupleDescInitEntry(tupdesc, attnum, attname, sql_atttypid,
|
||||
-1, 0);
|
||||
|
||||
/* now the category values columns */
|
||||
sql_attr = spi_tupdesc->attrs[2];
|
||||
sql_atttypid = sql_attr->atttypid;
|
||||
|
||||
for (i = 0; i < num_categories; i++)
|
||||
{
|
||||
attnum++;
|
||||
|
||||
sprintf(attname, "category_%d", i + 1);
|
||||
TupleDescInitEntry(tupdesc, attnum, attname, sql_atttypid,
|
||||
-1, 0);
|
||||
}
|
||||
|
||||
return tupdesc;
|
||||
}
|
||||
|
||||
/*
|
||||
* Return a properly quoted literal value.
|
||||
* Uses quote_literal in quote.c
|
||||
|
||||
@ -6,6 +6,13 @@ RETURNS setof float8
|
||||
AS 'MODULE_PATHNAME','normal_rand'
|
||||
LANGUAGE 'C' VOLATILE STRICT;
|
||||
|
||||
-- the generic crosstab function:
|
||||
CREATE OR REPLACE FUNCTION crosstab(text)
|
||||
RETURNS setof record
|
||||
AS 'MODULE_PATHNAME','crosstab'
|
||||
LANGUAGE 'C' STABLE STRICT;
|
||||
|
||||
-- examples of building custom type-specific crosstab functions:
|
||||
CREATE TYPE tablefunc_crosstab_2 AS
|
||||
(
|
||||
row_name TEXT,
|
||||
@ -45,6 +52,7 @@ RETURNS setof tablefunc_crosstab_4
|
||||
AS 'MODULE_PATHNAME','crosstab'
|
||||
LANGUAGE 'C' STABLE STRICT;
|
||||
|
||||
-- obsolete:
|
||||
CREATE OR REPLACE FUNCTION crosstab(text,int)
|
||||
RETURNS setof record
|
||||
AS 'MODULE_PATHNAME','crosstab'
|
||||
|
||||
Reference in New Issue
Block a user