OSDN Git Service

On Fri, 07 Sep 2001 01:34:46 -0400, Tom Lane wrote:
authorBruce Momjian <bruce@momjian.us>
Mon, 10 Sep 2001 14:55:08 +0000 (14:55 +0000)
committerBruce Momjian <bruce@momjian.us>
Mon, 10 Sep 2001 14:55:08 +0000 (14:55 +0000)
>there is still an unpatched reference to pg_description in
>getColumns(), in both jdbc1 and jdbc2.

This was introduced by Jeroen's patch (see
http://fts.postgresql.org/db/mw/msg.html?mid=1032468). Attached
is a patch that returns getColumns() to using "select
obj_description()" instead of direct access to pg_description,
as per the request by Tom.

I've incorporated Jeroen's fix to left outer join with
pg_attrdef instead of inner join, so getColumns() also returns
columns without a default value.

I have, however, not included Jeroen's attempt to combine
multiple queries into one huge multi-join query for better
performance, because:
1) I don't know how to do that using obj_description() instead
of direct access to pg_description
2) I don't think a performance improvement (if any) in this
method is very important

Because of the outer join, getColumns() will only work with a
backend >= 7.1. Since the conditional coding for 7.1/7.2 and
jdbc1/jdbc2 is already giving me headaches I didn't pursue a
pre-7.1 solution.

Regards,
Ren? Pijlman <rene@lab.applinet.nl>

src/interfaces/jdbc/org/postgresql/jdbc1/DatabaseMetaData.java
src/interfaces/jdbc/org/postgresql/jdbc2/DatabaseMetaData.java

index 986df4e..5ee83af 100644 (file)
@@ -13,7 +13,7 @@ import org.postgresql.util.PSQLException;
 /**
  * This class provides information about the database as a whole.
  *
- * $Id: DatabaseMetaData.java,v 1.31 2001/09/06 12:53:15 momjian Exp $
+ * $Id: DatabaseMetaData.java,v 1.32 2001/09/10 14:55:08 momjian Exp $
  *
  * <p>Many of the methods here return lists of information in ResultSets.  You
  * can use the normal ResultSet methods such as getString and getInt to
@@ -1895,19 +1895,21 @@ public class DatabaseMetaData implements java.sql.DatabaseMetaData
    */
   public java.sql.ResultSet getColumns(String catalog, String schemaPattern, String tableNamePattern, String columnNamePattern) throws SQLException
   {
+    // the field descriptors for the new ResultSet
+    Field f[] = new Field[18];
+    java.sql.ResultSet r;      // ResultSet for the SQL query that we need to do
     Vector v = new Vector();           // The new ResultSet tuple stuff
-       Field f[] = new Field[18];              // The field descriptors for the new ResultSet
-
-    f[ 0] = new Field(connection, "TABLE_CAT", iVarcharOid, 32);
-    f[ 1] = new Field(connection, "TABLE_SCHEM", iVarcharOid, 32);
-    f[ 2] = new Field(connection, "TABLE_NAME", iVarcharOid, 32);
-    f[ 3] = new Field(connection, "COLUMN_NAME", iVarcharOid, 32);
-    f[ 4] = new Field(connection, "DATA_TYPE", iInt2Oid, 2);
-    f[ 5] = new Field(connection, "TYPE_NAME", iVarcharOid, 32);
-    f[ 6] = new Field(connection, "COLUMN_SIZE", iInt4Oid, 4);
-    f[ 7] = new Field(connection, "BUFFER_LENGTH", iVarcharOid, 32);
-    f[ 8] = new Field(connection, "DECIMAL_DIGITS", iInt4Oid, 4);
-    f[ 9] = new Field(connection, "NUM_PREC_RADIX", iInt4Oid, 4);
+
+    f[0] = new Field(connection, "TABLE_CAT", iVarcharOid, 32);
+    f[1] = new Field(connection, "TABLE_SCHEM", iVarcharOid, 32);
+    f[2] = new Field(connection, "TABLE_NAME", iVarcharOid, 32);
+    f[3] = new Field(connection, "COLUMN_NAME", iVarcharOid, 32);
+    f[4] = new Field(connection, "DATA_TYPE", iInt2Oid, 2);
+    f[5] = new Field(connection, "TYPE_NAME", iVarcharOid, 32);
+    f[6] = new Field(connection, "COLUMN_SIZE", iInt4Oid, 4);
+    f[7] = new Field(connection, "BUFFER_LENGTH", iVarcharOid, 32);
+    f[8] = new Field(connection, "DECIMAL_DIGITS", iInt4Oid, 4);
+    f[9] = new Field(connection, "NUM_PREC_RADIX", iInt4Oid, 4);
     f[10] = new Field(connection, "NULLABLE", iInt4Oid, 4);
     f[11] = new Field(connection, "REMARKS", iVarcharOid, 32);
     f[12] = new Field(connection, "COLUMN_DEF", iVarcharOid, 32);
@@ -1917,105 +1919,93 @@ public class DatabaseMetaData implements java.sql.DatabaseMetaData
     f[16] = new Field(connection, "ORDINAL_POSITION", iInt4Oid,4);
     f[17] = new Field(connection, "IS_NULLABLE", iVarcharOid, 32);
 
-       StringBuffer sql = new StringBuffer(512);
-
-       sql.append("select " +
-               (connection.haveMinimumServerVersion("7.2") ? "a.attrelid, " : "a.oid, ") +
-               "    c.relname, " +
-               "    a.attname, " +
-               "    a.atttypid, " +
-               "    a.attnum, " +
-               "    a.attnotnull, " +
-               "    a.attlen, " +
-               "    a.atttypmod, " +
-               "    d.adsrc, " +
-               "    t.typname, " +
-               "    e.description " +
-               "from" +
-               "    (" +
-               "        (pg_class c inner join pg_attribute a on" +
-               "            (" +
-               "                a.attrelid=c.oid");
-
-       if ((tableNamePattern != null) && ! tableNamePattern.equals("%")) {
-               sql.append("                and c.relname like \'" + tableNamePattern + "\'");
-       }
+    // Added by Stefan Andreasen <stefan@linux.kapow.dk>
+    // If the pattern are  null then set them to %
+    if (tableNamePattern == null) tableNamePattern="%";
+    if (columnNamePattern == null) columnNamePattern="%";
 
-       if ((columnNamePattern != null) && ! columnNamePattern.equals("%")) {
-               sql.append("                and a.attname like \'" + columnNamePattern + "\'");
-       }
+    // Now form the query
+       String query =
+           "select " +
+               (connection.haveMinimumServerVersion("7.2") ? "a.attrelid" : "a.oid") +
+               ",c.relname,a.attname,a.atttypid," +
+               "a.attnum,a.attnotnull,a.attlen,a.atttypmod,d.adsrc " +
+               "from (pg_class c inner join pg_attribute a " +
+               "on (c.oid=a.attrelid) ) " +
+               "left outer join pg_attrdef d " +
+               "on (c.oid=d.adrelid and d.adnum=a.attnum) " +
+               "where " +
+               "c.relname like '"+tableNamePattern.toLowerCase()+"' and " +
+               "a.attname like '"+columnNamePattern.toLowerCase()+"' and " +
+               "a.attnum>0 " +
+               "order by c.relname,a.attnum";
+
+    r = connection.ExecSQL(query);
 
-       sql.append(
-               "                and a.attnum > 0" +
-               "            )" +
-               "        ) inner join pg_type t on" +
-               "            (" +
-               "                t.oid = a.atttypid" +
-               "            )" +
-               "    )" +
-               "    left outer join pg_attrdef d on" +
-               "        (" +
-               "            c.oid = d.adrelid" +
-               "            and a.attnum = d.adnum" +
-               "        )" +
-               "    left outer join pg_description e on" +
-               "        (" +
-               "            e.objoid = a.attrelid");
-
-       if (connection.haveMinimumServerVersion("7.2")) {
-               sql.append(
-                       "            and e.objsubid = a.attnum" +
-                       "            and e.classoid = (select oid from pg_class where relname = \'pg_class\')");
-       }
+    while(r.next()) {
+       byte[][] tuple = new byte[18][0];
 
-       sql.append(
-               "        ) " +
-               "order by" +
-               "    c.relname, a.attnum");
-
-       java.sql.ResultSet r = connection.ExecSQL(sql.toString());
-       while (r.next()) {
-               byte[][] tuple = new byte[18][0];
-
-               String nullFlag = r.getString(6);
-               String typname = r.getString(10);
-
-               tuple[0] = "".getBytes();                               // Catalog name
-               tuple[1] = "".getBytes();                               // Schema name
-               tuple[2] = r.getBytes(2);                               // Table name
-               tuple[3] = r.getBytes(3);                               // Column name
-               tuple[4] = Integer.toString(connection.getSQLType(typname)).getBytes(); // Data type
-               tuple[5] = typname.getBytes();                  // Type name
-
-               // Column size
-               // Looking at the psql source,
-               // I think the length of a varchar as specified when the table was created
-               // should be extracted from atttypmod which contains this length + sizeof(int32)
-               if (typname.equals("bpchar") || typname.equals("varchar")) {
-                       int atttypmod = r.getInt(8);
-                       tuple[6] = Integer.toString(atttypmod != -1 ? atttypmod - VARHDRSZ : 0).getBytes();
-               } else {
-                       tuple[6] = r.getBytes(7);
-               }
-
-               tuple[7] = null;                                                // Buffer length
-               tuple[8] = "0".getBytes();                              // Decimal Digits - how to get this?
-               tuple[9] = "10".getBytes();                             // Num Prec Radix - assume decimal
-               tuple[10] = Integer.toString(nullFlag.equals("f") ?
-                       java.sql.DatabaseMetaData.columnNullable :
-                       java.sql.DatabaseMetaData.columnNoNulls).getBytes();    // Nullable
-               tuple[11] = r.getBytes(11);                     // Description (if any)
-               tuple[12] = r.getBytes(9);                              // Column default
-               tuple[13] = null;                                               // sql data type (unused)
-               tuple[14] = null;                                               // sql datetime sub (unused)
-               tuple[15] = tuple[6];                                   // char octet length
-               tuple[16] = r.getBytes(5);                              // ordinal position
-               tuple[17] = (nullFlag.equals("f") ? "YES" : "NO").getBytes();   // Is nullable
-
-               v.addElement(tuple);
-       }
-       r.close();
+       // Fetch the description for the table (if any)
+       String getDescriptionStatement =
+               connection.haveMinimumServerVersion("7.2") ?
+               "select col_description(" + r.getInt(1) + "," + r.getInt(5) + ")" :
+           "select description from pg_description where objoid=" + r.getInt(1);
+
+       java.sql.ResultSet dr = connection.ExecSQL(getDescriptionStatement);
 
+       if(((org.postgresql.ResultSet)dr).getTupleCount()==1) {
+         dr.next();
+         tuple[11] = dr.getBytes(1);
+       } else
+               tuple[11] = null;
+       dr.close();
+
+       tuple[0] = "".getBytes();       // Catalog name
+       tuple[1] = "".getBytes();       // Schema name
+       tuple[2] = r.getBytes(2);       // Table name
+       tuple[3] = r.getBytes(3);       // Column name
+
+       dr = connection.ExecSQL("select typname from pg_type where oid = "+r.getString(4));
+       dr.next();
+       String typname=dr.getString(1);
+       dr.close();
+        tuple[4] = Integer.toString(connection.getSQLType(typname)).getBytes();        // Data type
+       tuple[5] = typname.getBytes();  // Type name
+
+       // Column size
+       // Looking at the psql source,
+       // I think the length of a varchar as specified when the table was created
+       // should be extracted from atttypmod which contains this length + sizeof(int32)
+       if (typname.equals("bpchar") || typname.equals("varchar")) {
+         int atttypmod = r.getInt(8);
+         tuple[6] = Integer.toString(atttypmod != -1 ? atttypmod - VARHDRSZ : 0).getBytes();
+       } else
+         tuple[6] = r.getBytes(7);
+
+       tuple[7] = null;        // Buffer length
+
+       tuple[8] = "0".getBytes();      // Decimal Digits - how to get this?
+       tuple[9] = "10".getBytes();     // Num Prec Radix - assume decimal
+
+       // tuple[10] is below
+       // tuple[11] is above
+
+       tuple[12] = r.getBytes(9);      // column default
+
+       tuple[13] = null;       // sql data type (unused)
+       tuple[14] = null;       // sql datetime sub (unused)
+
+       tuple[15] = tuple[6];   // char octet length
+
+       tuple[16] = r.getBytes(5);      // ordinal position
+
+       String nullFlag = r.getString(6);
+       tuple[10] = Integer.toString(nullFlag.equals("f")?java.sql.DatabaseMetaData.columnNullable:java.sql.DatabaseMetaData.columnNoNulls).getBytes(); // Nullable
+       tuple[17] = (nullFlag.equals("f")?"YES":"NO").getBytes();       // is nullable
+
+       v.addElement(tuple);
+      }
+    r.close();
     return new ResultSet(connection, f, v, "OK", 1);
   }
 
index 4d39f87..8ff2a3f 100644 (file)
@@ -13,7 +13,7 @@ import org.postgresql.util.PSQLException;
 /**
  * This class provides information about the database as a whole.
  *
- * $Id: DatabaseMetaData.java,v 1.35 2001/09/06 12:53:15 momjian Exp $
+ * $Id: DatabaseMetaData.java,v 1.36 2001/09/10 14:55:08 momjian Exp $
  *
  * <p>Many of the methods here return lists of information in ResultSets.  You
  * can use the normal ResultSet methods such as getString and getInt to
@@ -1895,19 +1895,21 @@ public class DatabaseMetaData implements java.sql.DatabaseMetaData
    */
   public java.sql.ResultSet getColumns(String catalog, String schemaPattern, String tableNamePattern, String columnNamePattern) throws SQLException
   {
+    // the field descriptors for the new ResultSet
+    Field f[] = new Field[18];
+    java.sql.ResultSet r;      // ResultSet for the SQL query that we need to do
     Vector v = new Vector();           // The new ResultSet tuple stuff
-       Field f[] = new Field[18];              // The field descriptors for the new ResultSet
-
-    f[ 0] = new Field(connection, "TABLE_CAT", iVarcharOid, 32);
-    f[ 1] = new Field(connection, "TABLE_SCHEM", iVarcharOid, 32);
-    f[ 2] = new Field(connection, "TABLE_NAME", iVarcharOid, 32);
-    f[ 3] = new Field(connection, "COLUMN_NAME", iVarcharOid, 32);
-    f[ 4] = new Field(connection, "DATA_TYPE", iInt2Oid, 2);
-    f[ 5] = new Field(connection, "TYPE_NAME", iVarcharOid, 32);
-    f[ 6] = new Field(connection, "COLUMN_SIZE", iInt4Oid, 4);
-    f[ 7] = new Field(connection, "BUFFER_LENGTH", iVarcharOid, 32);
-    f[ 8] = new Field(connection, "DECIMAL_DIGITS", iInt4Oid, 4);
-    f[ 9] = new Field(connection, "NUM_PREC_RADIX", iInt4Oid, 4);
+
+    f[0] = new Field(connection, "TABLE_CAT", iVarcharOid, 32);
+    f[1] = new Field(connection, "TABLE_SCHEM", iVarcharOid, 32);
+    f[2] = new Field(connection, "TABLE_NAME", iVarcharOid, 32);
+    f[3] = new Field(connection, "COLUMN_NAME", iVarcharOid, 32);
+    f[4] = new Field(connection, "DATA_TYPE", iInt2Oid, 2);
+    f[5] = new Field(connection, "TYPE_NAME", iVarcharOid, 32);
+    f[6] = new Field(connection, "COLUMN_SIZE", iInt4Oid, 4);
+    f[7] = new Field(connection, "BUFFER_LENGTH", iVarcharOid, 32);
+    f[8] = new Field(connection, "DECIMAL_DIGITS", iInt4Oid, 4);
+    f[9] = new Field(connection, "NUM_PREC_RADIX", iInt4Oid, 4);
     f[10] = new Field(connection, "NULLABLE", iInt4Oid, 4);
     f[11] = new Field(connection, "REMARKS", iVarcharOid, 32);
     f[12] = new Field(connection, "COLUMN_DEF", iVarcharOid, 32);
@@ -1917,105 +1919,93 @@ public class DatabaseMetaData implements java.sql.DatabaseMetaData
     f[16] = new Field(connection, "ORDINAL_POSITION", iInt4Oid,4);
     f[17] = new Field(connection, "IS_NULLABLE", iVarcharOid, 32);
 
-       StringBuffer sql = new StringBuffer(512);
-
-       sql.append("select " +
-               (connection.haveMinimumServerVersion("7.2") ? "a.attrelid, " : "a.oid, ") +
-               "    c.relname, " +
-               "    a.attname, " +
-               "    a.atttypid, " +
-               "    a.attnum, " +
-               "    a.attnotnull, " +
-               "    a.attlen, " +
-               "    a.atttypmod, " +
-               "    d.adsrc, " +
-               "    t.typname, " +
-               "    e.description " +
-               "from" +
-               "    (" +
-               "        (pg_class c inner join pg_attribute a on" +
-               "            (" +
-               "                a.attrelid=c.oid");
-
-       if ((tableNamePattern != null) && ! tableNamePattern.equals("%")) {
-               sql.append("                and c.relname like \'" + tableNamePattern + "\'");
-       }
+    // Added by Stefan Andreasen <stefan@linux.kapow.dk>
+    // If the pattern are  null then set them to %
+    if (tableNamePattern == null) tableNamePattern="%";
+    if (columnNamePattern == null) columnNamePattern="%";
 
-       if ((columnNamePattern != null) && ! columnNamePattern.equals("%")) {
-               sql.append("                and a.attname like \'" + columnNamePattern + "\'");
-       }
+    // Now form the query
+       String query =
+           "select " +
+               (connection.haveMinimumServerVersion("7.2") ? "a.attrelid" : "a.oid") +
+               ",c.relname,a.attname,a.atttypid," +
+               "a.attnum,a.attnotnull,a.attlen,a.atttypmod,d.adsrc " +
+               "from (pg_class c inner join pg_attribute a " +
+               "on (c.oid=a.attrelid) ) " +
+               "left outer join pg_attrdef d " +
+               "on (c.oid=d.adrelid and d.adnum=a.attnum) " +
+               "where " +
+               "c.relname like '"+tableNamePattern.toLowerCase()+"' and " +
+               "a.attname like '"+columnNamePattern.toLowerCase()+"' and " +
+               "a.attnum>0 " +
+               "order by c.relname,a.attnum";
+
+    r = connection.ExecSQL(query);
 
-       sql.append(
-               "                and a.attnum > 0" +
-               "            )" +
-               "        ) inner join pg_type t on" +
-               "            (" +
-               "                t.oid = a.atttypid" +
-               "            )" +
-               "    )" +
-               "    left outer join pg_attrdef d on" +
-               "        (" +
-               "            c.oid = d.adrelid" +
-               "            and a.attnum = d.adnum" +
-               "        )" +
-               "    left outer join pg_description e on" +
-               "        (" +
-               "            e.objoid = a.attrelid");
-
-       if (connection.haveMinimumServerVersion("7.2")) {
-               sql.append(
-                       "            and e.objsubid = a.attnum" +
-                       "            and e.classoid = (select oid from pg_class where relname = \'pg_class\')");
-       }
+    while(r.next()) {
+       byte[][] tuple = new byte[18][0];
 
-       sql.append(
-               "        ) " +
-               "order by" +
-               "    c.relname, a.attnum");
-
-       java.sql.ResultSet r = connection.ExecSQL(sql.toString());
-       while (r.next()) {
-               byte[][] tuple = new byte[18][0];
-
-               String nullFlag = r.getString(6);
-               String typname = r.getString(10);
-
-               tuple[0] = "".getBytes();                               // Catalog name
-               tuple[1] = "".getBytes();                               // Schema name
-               tuple[2] = r.getBytes(2);                               // Table name
-               tuple[3] = r.getBytes(3);                               // Column name
-               tuple[4] = Integer.toString(connection.getSQLType(typname)).getBytes(); // Data type
-               tuple[5] = typname.getBytes();                  // Type name
-
-               // Column size
-               // Looking at the psql source,
-               // I think the length of a varchar as specified when the table was created
-               // should be extracted from atttypmod which contains this length + sizeof(int32)
-               if (typname.equals("bpchar") || typname.equals("varchar")) {
-                       int atttypmod = r.getInt(8);
-                       tuple[6] = Integer.toString(atttypmod != -1 ? atttypmod - VARHDRSZ : 0).getBytes();
-               } else {
-                       tuple[6] = r.getBytes(7);
-               }
-
-               tuple[7] = null;                                                // Buffer length
-               tuple[8] = "0".getBytes();                              // Decimal Digits - how to get this?
-               tuple[9] = "10".getBytes();                             // Num Prec Radix - assume decimal
-               tuple[10] = Integer.toString(nullFlag.equals("f") ?
-                       java.sql.DatabaseMetaData.columnNullable :
-                       java.sql.DatabaseMetaData.columnNoNulls).getBytes();    // Nullable
-               tuple[11] = r.getBytes(11);                     // Description (if any)
-               tuple[12] = r.getBytes(9);                              // Column default
-               tuple[13] = null;                                               // sql data type (unused)
-               tuple[14] = null;                                               // sql datetime sub (unused)
-               tuple[15] = tuple[6];                                   // char octet length
-               tuple[16] = r.getBytes(5);                              // ordinal position
-               tuple[17] = (nullFlag.equals("f") ? "YES" : "NO").getBytes();   // Is nullable
-
-               v.addElement(tuple);
-       }
-       r.close();
+       // Fetch the description for the table (if any)
+       String getDescriptionStatement =
+               connection.haveMinimumServerVersion("7.2") ?
+               "select col_description(" + r.getInt(1) + "," + r.getInt(5) + ")" :
+           "select description from pg_description where objoid=" + r.getInt(1);
+
+       java.sql.ResultSet dr = connection.ExecSQL(getDescriptionStatement);
 
+       if(((org.postgresql.ResultSet)dr).getTupleCount()==1) {
+         dr.next();
+         tuple[11] = dr.getBytes(1);
+       } else
+               tuple[11] = null;
+       dr.close();
+
+       tuple[0] = "".getBytes();       // Catalog name
+       tuple[1] = "".getBytes();       // Schema name
+       tuple[2] = r.getBytes(2);       // Table name
+       tuple[3] = r.getBytes(3);       // Column name
+
+       dr = connection.ExecSQL("select typname from pg_type where oid = "+r.getString(4));
+       dr.next();
+       String typname=dr.getString(1);
+       dr.close();
+        tuple[4] = Integer.toString(connection.getSQLType(typname)).getBytes();        // Data type
+       tuple[5] = typname.getBytes();  // Type name
+
+       // Column size
+       // Looking at the psql source,
+       // I think the length of a varchar as specified when the table was created
+       // should be extracted from atttypmod which contains this length + sizeof(int32)
+       if (typname.equals("bpchar") || typname.equals("varchar")) {
+         int atttypmod = r.getInt(8);
+         tuple[6] = Integer.toString(atttypmod != -1 ? atttypmod - VARHDRSZ : 0).getBytes();
+       } else
+         tuple[6] = r.getBytes(7);
+
+       tuple[7] = null;        // Buffer length
+
+       tuple[8] = "0".getBytes();      // Decimal Digits - how to get this?
+       tuple[9] = "10".getBytes();     // Num Prec Radix - assume decimal
+
+       // tuple[10] is below
+       // tuple[11] is above
+
+       tuple[12] = r.getBytes(9);      // column default
+
+       tuple[13] = null;       // sql data type (unused)
+       tuple[14] = null;       // sql datetime sub (unused)
+
+       tuple[15] = tuple[6];   // char octet length
+
+       tuple[16] = r.getBytes(5);      // ordinal position
+
+       String nullFlag = r.getString(6);
+       tuple[10] = Integer.toString(nullFlag.equals("f")?java.sql.DatabaseMetaData.columnNullable:java.sql.DatabaseMetaData.columnNoNulls).getBytes(); // Nullable
+       tuple[17] = (nullFlag.equals("f")?"YES":"NO").getBytes();       // is nullable
+
+       v.addElement(tuple);
+      }
+    r.close();
     return new ResultSet(connection, f, v, "OK", 1);
   }