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Patch from Nic Ferrier to add support for result sets being cursor based

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so that rows can be fetched incrementally.  This is enabled by using
setFetchSize()
This commit is contained in:
Barry Lind
2003-02-04 09:20:12 +00:00
parent 2d1f940542
commit 16a30346c8
26 changed files with 430 additions and 233 deletions
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176
src/interfaces/jdbc/org/postgresql/jdbc1/AbstractJdbc1Statement.java
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@ -8,7 +8,7 @@ import java.util.Vector;
import org.postgresql.largeobject.*;
import org.postgresql.util.*;
/* $Header: /cvsroot/pgsql/src/interfaces/jdbc/org/postgresql/jdbc1/Attic/AbstractJdbc1Statement.java,v 1.14 2002/11/20 07:34:32 barry Exp $
/* $Header: /cvsroot/pgsql/src/interfaces/jdbc/org/postgresql/jdbc1/Attic/AbstractJdbc1Statement.java,v 1.15 2003/02/04 09:20:08 barry Exp $
* This class defines methods of the jdbc1 specification. This class is
* extended by org.postgresql.jdbc2.AbstractJdbc2Statement which adds the jdbc2
* methods. The real Statement class (for jdbc1) is org.postgresql.jdbc1.Jdbc1Statement
@ -19,12 +19,19 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
// The connection who created us
protected AbstractJdbc1Connection connection;
public org.postgresql.PGConnection getPGConnection() {
return connection;
}
/** The warnings chain. */
protected SQLWarning warnings = null;
/** Maximum number of rows to return, 0 = unlimited */
protected int maxrows = 0;
/** Number of rows to get in a batch. */
protected int fetchSize = 0;
/** Timeout (in seconds) for a query (not used) */
protected int timeout = 0;
@ -47,8 +54,10 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
private String[] m_origSqlFragments;
private String[] m_executeSqlFragments;
protected Object[] m_binds = new Object[0];
protected String[] m_bindTypes = new String[0];
private String m_statementName = null;
protected String m_statementName = null;
private boolean m_useServerPrepare = false;
private static int m_preparedCount = 1;
@ -67,6 +76,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
protected Object callResult;
public abstract java.sql.ResultSet createResultSet(org.postgresql.Field[] fields, Vector tuples, String status, int updateCount, long insertOID, boolean binaryCursor) throws SQLException;
public AbstractJdbc1Statement (AbstractJdbc1Connection connection)
{
@ -117,7 +127,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
}
/*
* Execute a SQL statement that retruns a single ResultSet
*
@ -132,11 +142,21 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
m_binds = new Object[0];
//If we have already created a server prepared statement, we need
//to deallocate the existing one
if (m_statementName != null) {
((AbstractJdbc1Connection)connection).ExecSQL("DEALLOCATE " + m_statementName);
m_statementName = null;
m_origSqlFragments = null;
m_executeSqlFragments = null;
if (m_statementName != null)
{
try
{
((AbstractJdbc1Connection)connection).execSQL("DEALLOCATE " + m_statementName);
}
catch (Exception e)
{
}
finally
{
m_statementName = null;
m_origSqlFragments = null;
m_executeSqlFragments = null;
}
}
return executeQuery();
}
@ -150,7 +170,11 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
*/
public java.sql.ResultSet executeQuery() throws SQLException
{
this.execute();
if (fetchSize > 0)
this.executeWithCursor();
else
this.execute();
while (result != null && !((AbstractJdbc1ResultSet)result).reallyResultSet())
result = ((AbstractJdbc1ResultSet)result).getNext();
if (result == null)
@ -175,7 +199,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
//If we have already created a server prepared statement, we need
//to deallocate the existing one
if (m_statementName != null) {
((AbstractJdbc1Connection)connection).ExecSQL("DEALLOCATE " + m_statementName);
((AbstractJdbc1Connection)connection).execSQL("DEALLOCATE " + m_statementName);
m_statementName = null;
m_origSqlFragments = null;
m_executeSqlFragments = null;
@ -219,7 +243,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
//If we have already created a server prepared statement, we need
//to deallocate the existing one
if (m_statementName != null) {
((AbstractJdbc1Connection)connection).ExecSQL("DEALLOCATE " + m_statementName);
((AbstractJdbc1Connection)connection).execSQL("DEALLOCATE " + m_statementName);
m_statementName = null;
m_origSqlFragments = null;
m_executeSqlFragments = null;
@ -317,7 +341,9 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
}
// New in 7.1, pass Statement so that ExecSQL can customise to it
result = ((AbstractJdbc1Connection)connection).ExecSQL(m_sqlFragments, m_binds, (java.sql.Statement)this);
result = org.postgresql.core.QueryExecutor.execute(m_sqlFragments,
m_binds,
(java.sql.Statement)this);
//If we are executing a callable statement function set the return data
if (isFunction)
@ -341,6 +367,102 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
}
}
/** version of execute which converts the query to a cursor.
*/
public boolean executeWithCursor() throws SQLException
{
if (isFunction && !returnTypeSet)
throw new PSQLException("postgresql.call.noreturntype");
if (isFunction)
{ // set entry 1 to dummy entry..
m_binds[0] = ""; // dummy entry which ensured that no one overrode
m_bindTypes[0] = PG_TEXT;
// and calls to setXXX (2,..) really went to first arg in a function call..
}
// New in 7.1, if we have a previous resultset then force it to close
// This brings us nearer to compliance, and helps memory management.
// Internal stuff will call ExecSQL directly, bypassing this.
if (result != null)
{
java.sql.ResultSet rs = getResultSet();
if (rs != null)
rs.close();
}
// I've pretty much ignored server prepared statements... can declare and prepare be
// used together?
// It's trivial to change this: you just have to resolve this issue
// of how to work out whether there's a function call. If there isn't then the first
// element of the array must be the bit that you extend to become the cursor
// decleration.
// The last thing that can go wrong is when the user supplies a cursor statement
// directly: the translation takes no account of that. I think we should just look
// for declare and stop the translation if we find it.
// The first thing to do is transform the statement text into the cursor form.
String[] origSqlFragments = m_sqlFragments;
m_sqlFragments = new String[origSqlFragments.length];
System.arraycopy(origSqlFragments, 0, m_sqlFragments, 0, origSqlFragments.length);
// Pinch the prepared count for our own nefarious purposes.
m_statementName = "JDBC_CURS_" + m_preparedCount++;
// The static bit to prepend to all querys.
String cursDecl = "BEGIN; DECLARE " + m_statementName + " CURSOR FOR ";
String endCurs = " FETCH FORWARD " + fetchSize + " FROM " + m_statementName + ";";
// Add the real query to the curs decleration.
// This is the bit that really makes the presumption about
// m_sqlFragments not being a function call.
if (m_sqlFragments.length < 1)
m_sqlFragments[0] = cursDecl + "SELECT NULL;";
else if (m_sqlFragments.length < 2)
{
if (m_sqlFragments[0].endsWith(";"))
m_sqlFragments[0] = cursDecl + m_sqlFragments[0] + endCurs;
else
m_sqlFragments[0] = cursDecl + m_sqlFragments[0] + ";" + endCurs;
}
else
{
m_sqlFragments[0] = cursDecl + m_sqlFragments[0];
if (m_sqlFragments[m_sqlFragments.length - 1].endsWith(";"))
m_sqlFragments[m_sqlFragments.length - 1] += endCurs;
else
m_sqlFragments[m_sqlFragments.length - 1] += (";" + endCurs);
}
result = org.postgresql.core.QueryExecutor.execute(m_sqlFragments,
m_binds,
(java.sql.Statement)this);
//If we are executing a callable statement function set the return data
if (isFunction)
{
if (!((AbstractJdbc1ResultSet)result).reallyResultSet())
throw new PSQLException("postgresql.call.noreturnval");
if (!result.next ())
throw new PSQLException ("postgresql.call.noreturnval");
callResult = result.getObject(1);
int columnType = result.getMetaData().getColumnType(1);
if (columnType != functionReturnType)
{
Object[] arr =
{ "java.sql.Types=" + columnType,
"java.sql.Types=" + functionReturnType
};
throw new PSQLException ("postgresql.call.wrongrtntype",arr);
}
result.close ();
return true;
}
else
{
return (result != null && ((AbstractJdbc1ResultSet)result).reallyResultSet());
}
}
/*
* setCursorName defines the SQL cursor name that will be used by
* subsequent execute methods. This name can then be used in SQL
@ -593,7 +715,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
// If using server prepared statements deallocate them
if (m_useServerPrepare && m_statementName != null) {
((AbstractJdbc1Connection)connection).ExecSQL("DEALLOCATE " + m_statementName);
((AbstractJdbc1Connection)connection).execSQL("DEALLOCATE " + m_statementName);
}
// Disasociate it from us (For Garbage Collection)
@ -1690,7 +1812,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
*/
public byte[] getBytes(int parameterIndex) throws SQLException
{
checkIndex (parameterIndex, Types.VARBINARY, "Bytes");
checkIndex (parameterIndex, Types.VARBINARY, Types.BINARY, "Bytes");
return ((byte [])callResult);
}
@ -1847,7 +1969,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
String l_sql = p_sql;
int index = l_sql.indexOf ("="); // is implied func or proc?
boolean isValid = true;
if (index != -1)
if (index > -1)
{
isFunction = true;
isValid = l_sql.indexOf ("?") < index; // ? before =
@ -1875,11 +1997,24 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
// sure that the parameter numbers are the same as in the original
// sql we add a dummy parameter in this case
l_sql = (isFunction ? "?" : "") + l_sql.substring (index + 4);
l_sql = "select " + l_sql + " as " + RESULT_COLUMN + ";";
return l_sql;
}
/** helperfunction for the getXXX calls to check isFunction and index == 1
* Compare BOTH type fields against the return type.
*/
protected void checkIndex (int parameterIndex, int type1, int type2, String getName)
throws SQLException
{
checkIndex (parameterIndex);
if (type1 != this.testReturn && type2 != this.testReturn)
throw new PSQLException("postgresql.call.wrongget",
new Object[]{"java.sql.Types=" + testReturn,
getName,
"java.sql.Types=" + type1});
}
/** helperfunction for the getXXX calls to check isFunction and index == 1
*/
protected void checkIndex (int parameterIndex, int type, String getName)
@ -1888,10 +2023,11 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
checkIndex (parameterIndex);
if (type != this.testReturn)
throw new PSQLException("postgresql.call.wrongget",
new Object[]{"java.sql.Types=" + testReturn,
getName,
"java.sql.Types=" + type});
new Object[]{"java.sql.Types=" + testReturn,
getName,
"java.sql.Types=" + type});
}
/** helperfunction for the getXXX calls to check isFunction and index == 1
* @param parameterIndex index of getXXX (index)
* check to make sure is a function and index == 1
@ -1912,7 +2048,7 @@ public abstract class AbstractJdbc1Statement implements org.postgresql.PGStateme
//If turning server prepared statements off deallocate statement
//and reset statement name
if (m_useServerPrepare != flag && !flag)
((AbstractJdbc1Connection)connection).ExecSQL("DEALLOCATE " + m_statementName);
((AbstractJdbc1Connection)connection).execSQL("DEALLOCATE " + m_statementName);
m_statementName = null;
m_useServerPrepare = flag;
} else {