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Commit 16a3034

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author
Barry Lind
committed
Patch from Nic Ferrier to add support for result sets being cursor based
so that rows can be fetched incrementally. This is enabled by using setFetchSize()
1 parent 2d1f940 commit 16a3034

26 files changed

+428
-231
lines changed

‎src/interfaces/jdbc/org/postgresql/core/QueryExecutor.java

Lines changed: 74 additions & 22 deletions
Original file line numberDiff line numberDiff line change
@@ -6,43 +6,80 @@
66
import java.sql.*;
77
import org.postgresql.*;
88
import org.postgresql.util.PSQLException;
9+
import org.postgresql.jdbc1.AbstractJdbc1Connection;
10+
import org.postgresql.jdbc1.AbstractJdbc1ResultSet;
11+
import org.postgresql.jdbc1.AbstractJdbc1Statement;
912

1013
/*
1114
* Executes a query on the backend.
1215
*
1316
* <p>The lifetime of a QueryExecutor object is from sending the query
1417
* until the response has been received from the backend.
1518
*
16-
* $Id: QueryExecutor.java,v 1.17 2002/11/14 05:35:45 barry Exp $
19+
* $Id: QueryExecutor.java,v 1.18 2003/02/04 09:20:08 barry Exp $
1720
*/
1821

1922
public class QueryExecutor
2023
{
24+
//This version of execute does not take an existing result set, but
25+
//creates a new one for the results of the query
26+
public static ResultSet execute (String[] p_sqlFrags,
27+
Object[] p_binds,
28+
java.sql.Statement statement)
29+
throws SQLException
30+
{
31+
QueryExecutor qe = new QueryExecutor();
32+
qe.m_sqlFrags = p_sqlFrags;
33+
qe.m_binds = p_binds;
34+
qe.statement = statement;
35+
if (statement != null)
36+
qe.maxRows = statement.getMaxRows();
37+
else
38+
qe.maxRows = 0;
2139

22-
private final String[] m_sqlFrags;
23-
private final Object[] m_binds;
24-
private final java.sql.Statement statement;
25-
private final PG_Stream pg_stream;
26-
private final org.postgresql.jdbc1.AbstractJdbc1Connection connection;
40+
qe.connection = (AbstractJdbc1Connection)((AbstractJdbc1Statement)statement).getPGConnection();
41+
qe.pg_stream = qe.connection.getPGStream();
2742

28-
public QueryExecutor(String[] p_sqlFrags, Object[] p_binds,
29-
java.sql.Statement statement,
30-
PG_Stream pg_stream,
31-
java.sql.Connection connection)
43+
return qe.execute();
44+
}
45+
46+
//This version of execute reuses an existing result set for the query
47+
//results, this is used when a result set is backed by a cursor and
48+
//more results are fetched
49+
public static void execute (String[] p_sqlFrags,
50+
Object[] p_binds,
51+
java.sql.ResultSet rs)
3252
throws SQLException
3353
{
34-
this.m_sqlFrags = p_sqlFrags;
35-
this.m_binds = p_binds;
36-
this.statement = statement;
37-
this.pg_stream = pg_stream;
38-
this.connection = (org.postgresql.jdbc1.AbstractJdbc1Connection)connection;
39-
40-
if (statement != null)
41-
maxRows = statement.getMaxRows();
54+
QueryExecutor qe = new QueryExecutor();
55+
qe.m_sqlFrags = p_sqlFrags;
56+
qe.m_binds = p_binds;
57+
qe.rs = rs;
58+
qe.statement = (java.sql.Statement)((AbstractJdbc1ResultSet)qe.rs).getPGStatement();
59+
if (qe.statement != null)
60+
qe.maxRows = qe.statement.getMaxRows();
4261
else
43-
maxRows = 0;
62+
qe.maxRows = 0;
63+
64+
qe.connection = (AbstractJdbc1Connection)((AbstractJdbc1Statement)qe.statement).getPGConnection();
65+
qe.pg_stream = qe.connection.getPGStream();
66+
67+
qe.execute();
4468
}
4569

70+
71+
private QueryExecutor ()
72+
{
73+
}
74+
75+
private String[] m_sqlFrags;
76+
private Object[] m_binds;
77+
private java.sql.Statement statement;
78+
private java.sql.ResultSet rs;
79+
80+
private AbstractJdbc1Connection connection;
81+
private PG_Stream pg_stream;
82+
4683
private Field[] fields = null;
4784
private Vector tuples = new Vector();
4885
private boolean binaryCursor = false;
@@ -51,10 +88,12 @@ public QueryExecutor(String[] p_sqlFrags, Object[] p_binds,
5188
private long insert_oid = 0;
5289
private int maxRows;
5390

91+
5492
/*
5593
* Execute a query on the backend.
94+
*
5695
*/
57-
public java.sql.ResultSet execute() throws SQLException
96+
private java.sql.ResultSet execute() throws SQLException
5897
{
5998

6099
StringBuffer errorMessage = null;
@@ -130,7 +169,18 @@ public java.sql.ResultSet execute() throws SQLException
130169
if ( errorMessage != null )
131170
throw new SQLException( errorMessage.toString() );
132171

133-
return connection.getResultSet(statement, fields, tuples, status, update_count, insert_oid, binaryCursor);
172+
173+
//if an existing result set was passed in reuse it, else
174+
//create a new one
175+
if (rs != null)
176+
{
177+
((org.postgresql.jdbc1.AbstractJdbc1ResultSet)rs).reInit(fields, tuples, status, update_count, insert_oid, binaryCursor);
178+
}
179+
else
180+
{
181+
rs = ((AbstractJdbc1Statement)statement).createResultSet(fields, tuples, status, update_count, insert_oid, binaryCursor);
182+
}
183+
return rs;
134184
}
135185
}
136186

@@ -145,10 +195,12 @@ private void sendQuery() throws SQLException
145195
for (int i = 0 ; i < m_binds.length ; ++i)
146196
{
147197
if (m_binds[i] == null)
148-
throw new PSQLException("postgresql.prep.param", new Integer(i + 1));
198+
throw new PSQLException("postgresql.prep.param (" + i + ")", new Integer(i + 1));
199+
149200
pg_stream.Send(connection.getEncoding().encode(m_sqlFrags[i]));
150201
pg_stream.Send(connection.getEncoding().encode(m_binds[i].toString()));
151202
}
203+
152204
pg_stream.Send(connection.getEncoding().encode(m_sqlFrags[m_binds.length]));
153205
pg_stream.SendChar(0);
154206
pg_stream.flush();

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