ResultSetMetaData Implementation Patch - Mailing list pgsql-jdbc

Hi

The patch attached implements the following Result Set Meta Information
methods in AbstractJdbc1ResultSetMetaData:

getTableName(...)
getSchemaName(...)
isNullable(...)
getColumnName(...)
getColumnLabel(...)

Also attached is a test case for the above methods.

And also thanks to Kris Jurka for his efforts in guiding me in the do's/do
nots of JDBC Driver development.


J-A













? ResultSetMetaInfoImplementation.diff.patch
? addrsmdtest.patch
? b
? message.eml
? org/postgresql/Test.java
? org/postgresql/test/jdbc2/ResultSetMetaDataTest.java
Index: org/postgresql/core/Field.java
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/core/Field.java,v
retrieving revision 1.2
diff -c -r1.2 Field.java
*** org/postgresql/core/Field.java    29 May 2003 03:21:32 -0000    1.2
--- org/postgresql/core/Field.java    14 Nov 2003 12:36:17 -0000
***************
*** 13,18 ****
--- 13,19 ----
  package org.postgresql.core;

  import java.sql.*;
+
  import org.postgresql.core.BaseConnection;

  /*
***************
*** 22,28 ****
      private int length;        // Internal Length of this field
      private int oid;        // OID of the type
      private int mod;        // type modifier of this field
!     private String name;        // Name of this field

      private BaseConnection conn;    // Connection Instantation

--- 23,35 ----
      private int length;        // Internal Length of this field
      private int oid;        // OID of the type
      private int mod;        // type modifier of this field
!     private String name;        // Name of this field (the column label)
!     private int tableOid; // OID of table ( zero if no table )
!     private int positionInTable;
!
!     // cache-fields
!     private Integer nullable;
!     private String columnName;

      private BaseConnection conn;    // Connection Instantation

***************
*** 57,62 ****
--- 64,90 ----
          this(conn, name, oid, length, 0);
      }

+     /*
+      * Construct a field based on the information fed to it.
+      *
+      * @param conn the connection this field came from
+      * @param name the name of the field
+      * @param oid the OID of the field
+      * @param length the length of the field
+      * @param tableOid the OID of the columns' table
+      * @param positionInTable the position of column in the table (first column is 1, second column is 2, etc...)
+      */
+     public Field(BaseConnection conn, String name, int oid, int length, int mod, int tableOid, int positionInTable)
+     {
+         this.conn = conn;
+         this.name = name;
+         this.oid = oid;
+         this.length = length;
+         this.mod = mod;
+         this.tableOid = tableOid;
+         this.positionInTable = positionInTable;
+     }
+
      /*
       * @return the oid of this Field's data type
       */
***************
*** 110,114 ****
--- 138,236 ----
      {
          return conn.getSQLType(oid);
      }
+
+     /*
+      * @return the columns' table oid, zero if no oid available
+      */
+     public int getTableOid()
+     {
+         return tableOid;
+     }
+
+     /*
+      * @return instantiated connection
+      */
+     public BaseConnection getConn()
+     {
+         return conn;
+     }
+
+     public int getPositionInTable()
+     {
+         return positionInTable;
+     }
+
+     public int getNullable() throws SQLException
+     {
+         if (nullable != null)
+         {
+             return nullable.intValue();
+         }
+         if (tableOid == 0)
+         {
+             nullable = new Integer(java.sql.ResultSetMetaData.columnNullableUnknown);
+             return nullable.intValue();
+         }
+         java.sql.Connection con = (java.sql.Connection) conn;
+         ResultSet res = null;
+         PreparedStatement ps = null;
+         try
+         {
+             ps = con.prepareStatement("SELECT attnotnull FROM pg_catalog.pg_attribute WHERE attrelid = ? AND attnum =
?;");
+             ps.setInt(1, tableOid);
+             ps.setInt(2, positionInTable);
+             res = ps.executeQuery();
+             int nullResult = java.sql.ResultSetMetaData.columnNullableUnknown;
+             if (res.next())
+             {
+                 nullResult = res.getBoolean(1) ? java.sql.ResultSetMetaData.columnNoNulls :
java.sql.ResultSetMetaData.columnNullable;
+             }
+             nullable = new Integer(nullResult);
+             return nullResult;
+         } finally
+         {
+             if (res != null)
+                 res.close();
+             if (ps != null)
+                 ps.close();
+         }
+     }
+
+     public String getColumnName() throws SQLException
+     {
+         if (conn.getPGProtocolVersionMajor() < 3) {
+             return name;
+         }
+         if (columnName != null)
+         {
+             return columnName;
+         }
+         if (tableOid == 0)
+         {
+             return columnName = "";
+         }
+         java.sql.Connection con = (java.sql.Connection) conn;
+         ResultSet res = null;
+         PreparedStatement ps = null;
+         try
+         {
+             ps = con.prepareStatement("SELECT attname FROM pg_catalog.pg_attribute WHERE attrelid = ? AND attnum =
?");
+             ps.setInt(1, tableOid);
+             ps.setInt(2, positionInTable);
+             res = ps.executeQuery();
+             String columnName = "";
+             if (res.next())
+             {
+                 columnName = res.getString(1);
+             }
+             return columnName;
+         } finally
+         {
+             if (res != null)
+                 res.close();
+             if (ps != null)
+                 ps.close();
+         }
+     }

  }
Index: org/postgresql/core/QueryExecutor.java
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/core/QueryExecutor.java,v
retrieving revision 1.27
diff -c -r1.27 QueryExecutor.java
*** org/postgresql/core/QueryExecutor.java    17 Sep 2003 08:21:36 -0000    1.27
--- org/postgresql/core/QueryExecutor.java    14 Nov 2003 12:36:19 -0000
***************
*** 21,27 ****

  public class QueryExecutor
  {
!     //This version of execute does not take an existing result set, but
      //creates a new one for the results of the query
      public static BaseResultSet execute(String[] p_sqlFrags,
                      Object[] p_binds,
--- 21,27 ----

  public class QueryExecutor
  {
!     //This version of execute does not take an existing result set, but
      //creates a new one for the results of the query
      public static BaseResultSet execute(String[] p_sqlFrags,
                      Object[] p_binds,
***************
*** 43,50 ****
          return qe.execute();
      }

!     //This version of execute reuses an existing result set for the query
!     //results, this is used when a result set is backed by a cursor and
      //more results are fetched
      public static void execute(String[] p_sqlFrags,
                      Object[] p_binds,
--- 43,50 ----
          return qe.execute();
      }

!     //This version of execute reuses an existing result set for the query
!     //results, this is used when a result set is backed by a cursor and
      //more results are fetched
      public static void execute(String[] p_sqlFrags,
                      Object[] p_binds,
***************
*** 111,117 ****

          PSQLException error = null;

!         if (pgStream == null)
          {
              throw new PSQLException("postgresql.con.closed", PSQLState.CONNECTION_DOES_NOT_EXIST);
          }
--- 111,117 ----

          PSQLException error = null;

!         if (pgStream == null)
          {
              throw new PSQLException("postgresql.con.closed", PSQLState.CONNECTION_DOES_NOT_EXIST);
          }
***************
*** 184,190 ****
                      case 'Z':
                          // read ReadyForQuery
                          //TODO: use size better
!                         if (pgStream.ReceiveIntegerR(4) != 5) throw new PSQLException("postgresql.con.setup",
PSQLState.CONNECTION_UNABLE_TO_CONNECT); 
                          //TODO: handle transaction status
                          char l_tStatus = (char)pgStream.ReceiveChar();
                          l_endQuery = true;
--- 184,190 ----
                      case 'Z':
                          // read ReadyForQuery
                          //TODO: use size better
!                         if (pgStream.ReceiveIntegerR(4) != 5) throw new PSQLException("postgresql.con.setup",
PSQLState.CONNECTION_UNABLE_TO_CONNECT);
                          //TODO: handle transaction status
                          char l_tStatus = (char)pgStream.ReceiveChar();
                          l_endQuery = true;
***************
*** 201,211 ****

              //if an existing result set was passed in reuse it, else
              //create a new one
!             if (rs != null)
              {
                  rs.reInit(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
!             else
              {
                  rs = statement.createResultSet(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
--- 201,211 ----

              //if an existing result set was passed in reuse it, else
              //create a new one
!             if (rs != null)
              {
                  rs.reInit(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
!             else
              {
                  rs = statement.createResultSet(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
***************
*** 218,224 ****

          StringBuffer errorMessage = null;

!         if (pgStream == null)
          {
              throw new PSQLException("postgresql.con.closed", PSQLState.CONNECTION_DOES_NOT_EXIST);
          }
--- 218,224 ----

          StringBuffer errorMessage = null;

!         if (pgStream == null)
          {
              throw new PSQLException("postgresql.con.closed", PSQLState.CONNECTION_DOES_NOT_EXIST);
          }
***************
*** 291,301 ****

              //if an existing result set was passed in reuse it, else
              //create a new one
!             if (rs != null)
              {
                  rs.reInit(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
!             else
              {
                  rs = statement.createResultSet(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
--- 291,301 ----

              //if an existing result set was passed in reuse it, else
              //create a new one
!             if (rs != null)
              {
                  rs.reInit(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
!             else
              {
                  rs = statement.createResultSet(fields, tuples, status, update_count, insert_oid, binaryCursor);
              }
***************
*** 414,420 ****
          //TODO: better handle the msg len
          int l_len = pgStream.ReceiveIntegerR(4);
          //read l_len -5 bytes (-4 for l_len and -1 for trailing \0)
!         status = connection.getEncoding().decode(pgStream.Receive(l_len-5));
          //now read and discard the trailing \0
          pgStream.Receive(1);
          try
--- 414,420 ----
          //TODO: better handle the msg len
          int l_len = pgStream.ReceiveIntegerR(4);
          //read l_len -5 bytes (-4 for l_len and -1 for trailing \0)
!         status = connection.getEncoding().decode(pgStream.Receive(l_len-5));
          //now read and discard the trailing \0
          pgStream.Receive(1);
          try
***************
*** 468,474 ****
      private void receiveFieldsV3() throws SQLException
      {
          //TODO: use the msgSize
-         //TODO: use the tableOid, and tablePosition
          if (fields != null)
              throw new PSQLException("postgresql.con.multres", PSQLState.CONNECTION_FAILURE);
          int l_msgSize = pgStream.ReceiveIntegerR(4);
--- 468,473 ----
***************
*** 477,491 ****

          for (int i = 0; i < fields.length; i++)
          {
!             String typeName = pgStream.ReceiveString(connection.getEncoding());
              int tableOid = pgStream.ReceiveIntegerR(4);
!             int tablePosition = pgStream.ReceiveIntegerR(2);
              int typeOid = pgStream.ReceiveIntegerR(4);
              int typeLength = pgStream.ReceiveIntegerR(2);
              int typeModifier = pgStream.ReceiveIntegerR(4);
              int formatType = pgStream.ReceiveIntegerR(2);
!             //TODO: use the extra values coming back
!             fields[i] = new Field(connection, typeName, typeOid, typeLength, typeModifier);
          }
      }
      /*
--- 476,489 ----

          for (int i = 0; i < fields.length; i++)
          {
!             String columnLabel = pgStream.ReceiveString(connection.getEncoding());
              int tableOid = pgStream.ReceiveIntegerR(4);
!             short positionInTable = (short)pgStream.ReceiveIntegerR(2);
              int typeOid = pgStream.ReceiveIntegerR(4);
              int typeLength = pgStream.ReceiveIntegerR(2);
              int typeModifier = pgStream.ReceiveIntegerR(4);
              int formatType = pgStream.ReceiveIntegerR(2);
!             fields[i] = new Field(connection, columnLabel, typeOid, typeLength, typeModifier, tableOid,
positionInTable);
          }
      }
      /*
***************
*** 501,511 ****

          for (int i = 0; i < fields.length; i++)
          {
!             String typeName = pgStream.ReceiveString(connection.getEncoding());
              int typeOid = pgStream.ReceiveIntegerR(4);
              int typeLength = pgStream.ReceiveIntegerR(2);
              int typeModifier = pgStream.ReceiveIntegerR(4);
!             fields[i] = new Field(connection, typeName, typeOid, typeLength, typeModifier);
          }
      }
  }
--- 499,509 ----

          for (int i = 0; i < fields.length; i++)
          {
!             String columnLabel = pgStream.ReceiveString(connection.getEncoding());
              int typeOid = pgStream.ReceiveIntegerR(4);
              int typeLength = pgStream.ReceiveIntegerR(2);
              int typeModifier = pgStream.ReceiveIntegerR(4);
!             fields[i] = new Field(connection, columnLabel, typeOid, typeLength, typeModifier);
          }
      }
  }
Index: org/postgresql/jdbc1/AbstractJdbc1ResultSetMetaData.java
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/jdbc1/AbstractJdbc1ResultSetMetaData.java,v
retrieving revision 1.6
diff -c -r1.6 AbstractJdbc1ResultSetMetaData.java
*** org/postgresql/jdbc1/AbstractJdbc1ResultSetMetaData.java    13 Sep 2003 04:02:15 -0000    1.6
--- org/postgresql/jdbc1/AbstractJdbc1ResultSetMetaData.java    14 Nov 2003 12:36:21 -0000
***************
*** 4,19 ****
  import org.postgresql.core.Field;
  import org.postgresql.util.PSQLException;
  import org.postgresql.util.PSQLState;
! import java.sql.SQLException;
! import java.sql.Types;
! import java.util.Vector;

  public abstract class AbstractJdbc1ResultSetMetaData
  {
-
      protected Vector rows;
      protected Field[] fields;

      /*
       *    Initialise for a result with a tuple set and
       *    a field descriptor set
--- 4,21 ----
  import org.postgresql.core.Field;
  import org.postgresql.util.PSQLException;
  import org.postgresql.util.PSQLState;
!
! import java.sql.*;
! import java.util.*;

  public abstract class AbstractJdbc1ResultSetMetaData
  {
      protected Vector rows;
      protected Field[] fields;

+     private Hashtable tableNameCache;
+     private Hashtable schemaNameCache;
+
      /*
       *    Initialise for a result with a tuple set and
       *    a field descriptor set
***************
*** 131,143 ****
       */
      public int isNullable(int column) throws SQLException
      {
!         /*
!          * TODO This needs a real implementation, taking into account columns
!          * defined with NOT NULL or PRIMARY KEY, CHECK constraints, views,
!          * functions etc.
!          */
!         return java.sql.ResultSetMetaData.columnNullableUnknown;
!     }

      /*
       * Is the column a signed number? In PostgreSQL, all numbers
--- 133,141 ----
       */
      public int isNullable(int column) throws SQLException
      {
!         Field field = getField(column);
!         return field.getNullable();
!       }

      /*
       * Is the column a signed number? In PostgreSQL, all numbers
***************
*** 225,240 ****
      }

      /*
-      * What is the suggested column title for use in printouts and
-      * displays?  We suggest the ColumnName!
-      *
       * @param column the first column is 1, the second is 2, etc.
       * @return the column label
       * @exception SQLException if a database access error occurs
       */
      public String getColumnLabel(int column) throws SQLException
      {
!         return getColumnName(column);
      }

      /*
--- 223,238 ----
      }

      /*
       * @param column the first column is 1, the second is 2, etc.
       * @return the column label
       * @exception SQLException if a database access error occurs
       */
      public String getColumnLabel(int column) throws SQLException
      {
!         Field f = getField(column);
!         if (f != null)
!             return f.getName();
!         return "field" + column;
      }

      /*
***************
*** 246,270 ****
       */
      public String getColumnName(int column) throws SQLException
      {
!         Field f = getField(column);
!         if (f != null)
!             return f.getName();
!         return "field" + column;
      }

      /*
-      * What is a column's table's schema?  This relies on us knowing
-      * the table name....which I don't know how to do as yet.  The
-      * JDBC specification allows us to return "" if this is not
-      * applicable.
-      *
       * @param column the first column is 1, the second is 2...
!      * @return the Schema
       * @exception SQLException if a database access error occurs
       */
      public String getSchemaName(int column) throws SQLException
      {
!         return "";
      }

      /*
--- 244,300 ----
       */
      public String getColumnName(int column) throws SQLException
      {
!         Field field = getField(column);
!         return field.getColumnName();
      }

      /*
       * @param column the first column is 1, the second is 2...
!      * @return the Schema Name
       * @exception SQLException if a database access error occurs
       */
      public String getSchemaName(int column) throws SQLException
      {
!         Field field = getField(column);
!         if (field.getTableOid() == 0)
!         {
!             return "";
!         }
!         Integer tableOid = new Integer(field.getTableOid());
!         if (schemaNameCache == null)
!         {
!             schemaNameCache = new Hashtable();
!         }
!         String schemaName = (String) schemaNameCache.get(tableOid);
!         if (schemaName != null)
!         {
!             return schemaName;
!         } else
!         {
!             java.sql.Connection con = (java.sql.Connection) field.getConn();
!             ResultSet res = null;
!             PreparedStatement ps = null;
!             try
!             {
!                 String sql = "SELECT n.nspname FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n WHERE n.oid =
c.relnamespaceAND c.oid = ?;"; 
!                 ps = con.prepareStatement(sql);
!                 ps.setInt(1, tableOid.intValue());
!                 res = ps.executeQuery();
!                 schemaName = "";
!                 if (res.next())
!                 {
!                     schemaName = res.getString(1);
!                 }
!                 schemaNameCache.put(tableOid, schemaName);
!                 return schemaName;
!             } finally
!             {
!                 if (res != null)
!                     res.close();
!                 if (ps != null)
!                     ps.close();
!             }
!         }
      }

      /*
***************
*** 341,357 ****
      }

      /*
-      * Whats a column's table's name?  How do I find this out?    Both
-      * getSchemaName() and getCatalogName() rely on knowing the table
-      * Name, so we need this before we can work on them.
-      *
       * @param column the first column is 1, the second is 2...
       * @return column name, or "" if not applicable
       * @exception SQLException if a database access error occurs
       */
      public String getTableName(int column) throws SQLException
      {
!         return "";
      }

      /*
--- 371,421 ----
      }

      /*
       * @param column the first column is 1, the second is 2...
       * @return column name, or "" if not applicable
       * @exception SQLException if a database access error occurs
       */
      public String getTableName(int column) throws SQLException
      {
!         Field field = getField(column);
!         if (field.getTableOid() == 0)
!         {
!             return "";
!         }
!         Integer tableOid = new Integer(field.getTableOid());
!         if (tableNameCache == null)
!         {
!             tableNameCache = new Hashtable();
!         }
!         String tableName = (String) tableNameCache.get(tableOid);
!         if (tableName != null)
!         {
!             return tableName;
!         } else
!         {
!             java.sql.Connection con = (java.sql.Connection) field.getConn();
!             ResultSet res = null;
!             PreparedStatement ps = null;
!             try
!             {
!                 ps = con.prepareStatement("SELECT relname FROM pg_catalog.pg_class WHERE oid = ?");
!                 ps.setInt(1, tableOid.intValue());
!                 res = ps.executeQuery();
!                 tableName = "";
!                 if (res.next())
!                 {
!                     tableName = res.getString(1);
!                 }
!                 tableNameCache.put(tableOid, tableName);
!                 return tableName;
!             } finally
!             {
!                 if (res != null)
!                     res.close();
!                 if (ps != null)
!                     ps.close();
!             }
!         }
      }

      /*
Index: org/postgresql/jdbc2/AbstractJdbc2ResultSetMetaData.java
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/jdbc2/AbstractJdbc2ResultSetMetaData.java,v
retrieving revision 1.5
diff -c -r1.5 AbstractJdbc2ResultSetMetaData.java
*** org/postgresql/jdbc2/AbstractJdbc2ResultSetMetaData.java    13 Sep 2003 04:02:15 -0000    1.5
--- org/postgresql/jdbc2/AbstractJdbc2ResultSetMetaData.java    14 Nov 2003 12:36:23 -0000
***************
*** 119,141 ****
      }

      /*
-      * Indicates the nullability of values in the designated column.
-      *
-      * @param column the first column is 1, the second is 2...
-      * @return one of the columnNullable values
-      * @exception SQLException if a database access error occurs
-      */
-     public int isNullable(int column) throws SQLException
-     {
-         /*
-          * TODO This needs a real implementation, taking into account columns
-          * defined with NOT NULL or PRIMARY KEY, CHECK constraints, views,
-          * functions etc.
-          */
-         return java.sql.ResultSetMetaData.columnNullableUnknown;
-     }
-
-     /*
       * Is the column a signed number? In PostgreSQL, all numbers
       * are signed, so this is trivial.    However, strings are not
       * signed (duh!)
--- 119,124 ----
***************
*** 221,269 ****
      }

      /*
-      * What is the suggested column title for use in printouts and
-      * displays?  We suggest the ColumnName!
-      *
-      * @param column the first column is 1, the second is 2, etc.
-      * @return the column label
-      * @exception SQLException if a database access error occurs
-      */
-     public String getColumnLabel(int column) throws SQLException
-     {
-         return getColumnName(column);
-     }
-
-     /*
-      * What's a column's name?
-      *
-      * @param column the first column is 1, the second is 2, etc.
-      * @return the column name
-      * @exception SQLException if a database access error occurs
-      */
-     public String getColumnName(int column) throws SQLException
-     {
-         Field f = getField(column);
-         if (f != null)
-             return f.getName();
-         return "field" + column;
-     }
-
-     /*
-      * What is a column's table's schema?  This relies on us knowing
-      * the table name....which I don't know how to do as yet.  The
-      * JDBC specification allows us to return "" if this is not
-      * applicable.
-      *
-      * @param column the first column is 1, the second is 2...
-      * @return the Schema
-      * @exception SQLException if a database access error occurs
-      */
-     public String getSchemaName(int column) throws SQLException
-     {
-         return "";
-     }
-
-     /*
       * What is a column's number of decimal digits.
       *
       * @param column the first column is 1, the second is 2...
--- 204,209 ----
***************
*** 336,354 ****
          }
      }

-     /*
-      * Whats a column's table's name?  How do I find this out?    Both
-      * getSchemaName() and getCatalogName() rely on knowing the table
-      * Name, so we need this before we can work on them.
-      *
-      * @param column the first column is 1, the second is 2...
-      * @return column name, or "" if not applicable
-      * @exception SQLException if a database access error occurs
-      */
-     public String getTableName(int column) throws SQLException
-     {
-         return "";
-     }

      /*
       * What's a column's table's catalog name?  As with getSchemaName(),
--- 276,281 ----
Index: org/postgresql/test/jdbc2/Jdbc2TestSuite.java
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/interfaces/jdbc/org/postgresql/test/jdbc2/Jdbc2TestSuite.java,v
retrieving revision 1.7
diff -c -r1.7 Jdbc2TestSuite.java
*** org/postgresql/test/jdbc2/Jdbc2TestSuite.java    22 Sep 2003 05:38:01 -0000    1.7
--- org/postgresql/test/jdbc2/Jdbc2TestSuite.java    14 Nov 2003 12:36:24 -0000
***************
*** 35,40 ****
--- 35,41 ----

          // ResultSet
          suite.addTestSuite(ResultSetTest.class);
+         suite.addTestSuite(ResultSetMetaDataTest.class);

          // Time, Date, Timestamp
          suite.addTestSuite(DateTest.class);
package org.postgresql.test.jdbc2;

import org.postgresql.test.TestUtil;
import junit.framework.TestCase;
import java.sql.*;

public class ResultSetMetaDataTest extends TestCase
{

    private Connection conn;
    private Statement stmt;
    private ResultSet rs;
    private ResultSetMetaData rsmd;

    public ResultSetMetaDataTest(String name)
    {
        super(name);
    }

    protected void setUp() throws Exception
    {
        conn = TestUtil.openDB();
        TestUtil.createTable(conn, "rsmd1", "a int primary key, b text, c decimal(10,2)");
        stmt = conn.createStatement();
        rs = stmt.executeQuery("SELECT a,b,c,a+c as total,oid FROM rsmd1");
        rsmd = rs.getMetaData();
    }

    protected void tearDown() throws Exception
    {
        TestUtil.dropTable(conn, "rsmd1");
        TestUtil.closeDB(conn);
        rs.close();
        stmt.close();
        rsmd = null;
        rs = null;
        stmt = null;
        conn = null;
    }

    public void testGetColumnCount() throws SQLException {
        assertTrue(rsmd.getColumnCount() == 5);
    }

    public void testGetColumnLabel() throws SQLException {
        assertTrue(rsmd.getColumnLabel(1).equals("a"));
        assertTrue(rsmd.getColumnLabel(4).equals("total"));
    }

    public void testGetColumnName() throws SQLException {
        assertTrue(rsmd.getColumnName(1).equals("a"));
        assertTrue(rsmd.getColumnName(5).equals("oid"));
        System.out.println(">>"+rsmd.getColumnName(4));
        if (TestUtil.haveMinimumServerVersion(conn,"7.4")) {
            assertTrue(rsmd.getColumnName(4).equals(""));
        }
    }

    public void testGetColumnType() throws SQLException {
        assertTrue(rsmd.getColumnType(1) == Types.INTEGER);
        assertTrue(rsmd.getColumnType(2) == Types.VARCHAR);
    }

    public void testGetColumnTypeName() throws SQLException {
        assertTrue(rsmd.getColumnTypeName(1).equals("int4"));
        assertTrue(rsmd.getColumnTypeName(2).equals("text"));
    }

    public void testGetPrecision() throws SQLException {
        assertTrue(rsmd.getPrecision(3) == 10);
    }

    public void testGetScale() throws SQLException {
        assertTrue(rsmd.getScale(3) == 2);
    }

    public void testGetSchemaName() throws SQLException {
        if (TestUtil.haveMinimumServerVersion(conn,"7.4")) {
            assertTrue(rsmd.getSchemaName(1).equals("public"));
            assertTrue(rsmd.getSchemaName(4).equals(""));
        }
    }

    public void testGetTableName() throws SQLException {
        if (TestUtil.haveMinimumServerVersion(conn,"7.4")) {
            assertTrue(rsmd.getTableName(1).equals("rsmd1"));
            assertTrue(rsmd.getTableName(4).equals(""));
        }
    }

    public void testIsNullable() throws SQLException {
        if (TestUtil.haveMinimumServerVersion(conn,"7.4")) {
            assertTrue(rsmd.isNullable(1) == ResultSetMetaData.columnNoNulls);
            assertTrue(rsmd.isNullable(2) == ResultSetMetaData.columnNullable);
            assertTrue(rsmd.isNullable(4) == ResultSetMetaData.columnNullableUnknown);
        } else {
            assertTrue(rsmd.isNullable(1) == ResultSetMetaData.columnNullableUnknown);
        }
    }

}