ODBC: MS Access could not link to a table with unique index or primary key.

h2/src/main/org/h2/server/pg/PgServer.java

@@ -46,6 +46,11 @@ public class PgServer implements Service {
      */
     public static final int PG_TYPE_VARCHAR = 1043;
 
+    /**
+     * The integer array type (for the column pg_index.indkey).
+     */
+    public static final int PG_TYPE_INT2VECTOR = 22;
+
     private static final int PG_TYPE_BOOL = 16;
     private static final int PG_TYPE_BYTEA = 17;
     private static final int PG_TYPE_BPCHAR = 1042;
@@ -269,7 +274,7 @@ public class PgServer implements Service {
             if (rs.next()) {
                 return rs.getString(1);
             }
-            return null;
+            return "";
         }
         PreparedStatement prep = conn.prepareStatement("select column_name from information_schema.indexes where id=? and ordinal_position=?");
         prep.setInt(1, indexId);
@@ -278,7 +283,7 @@ public class PgServer implements Service {
         if (rs.next()) {
             return rs.getString(1);
         }
-        return null;
+        return "";
     }
 
     /**

h2/src/main/org/h2/server/pg/PgServerThread.java

@@ -516,9 +516,16 @@ public class PgServerThread implements Runnable {
                 int[] precision = new int[columns];
                 String[] names = new String[columns];
                 for (int i = 0; i < columns; i++) {
-                    names[i] = meta.getColumnName(i + 1);
+                    String name = meta.getColumnName(i + 1);
+                    names[i] = name;
                     int type = meta.getColumnType(i + 1);
                     type = PgServer.convertType(type);
+                    // the ODBC client needs the column pg_catalog.pg_index
+                    // to be of type 'int2vector'
+                    // if (name.equalsIgnoreCase("indkey") &&
+                    //         "pg_index".equalsIgnoreCase(meta.getTableName(i + 1))) {
+                    //     type = PgServer.PG_TYPE_INT2VECTOR;
+                    // }
                     precision[i] = meta.getColumnDisplaySize(i + 1);
                     server.checkType(type);
                     types[i] = type;

h2/src/main/org/h2/server/pg/pg_catalog.sql

@@ -72,6 +72,15 @@ merge into pg_catalog.pg_type values(
     0,
     -1
 );
+merge into pg_catalog.pg_type values(
+    22,
+    'int2vector',
+    (select oid from pg_catalog.pg_namespace where nspname = 'pg_catalog'),
+    -1,
+    'c',
+    0,
+    -1
+);
 
 create view pg_catalog.pg_class -- (oid, relname, relnamespace, relkind, relam, reltuples, relpages, relhasrules, relhasoids)
 as
@@ -134,10 +143,10 @@ select
     t.id attrelid,
     c.column_name attname,
     pg_convertType(data_type) atttypid,
-    -1 attlen,
+    case when numeric_precision > 255 then -1 else numeric_precision end attlen,
     c.ordinal_position attnum,
     -1 atttypmod,
-    false attnotnull,
+    case c.is_nullable when 'YES' then false else true end attnotnull,
     false attisdropped,
     false atthasdef
 from information_schema.tables t, information_schema.columns c
@@ -149,10 +158,10 @@ select
     i.id attrelid,
     c.column_name attname,
     pg_convertType(data_type) atttypid,
-    -1 attlen,
+    case when numeric_precision > 255 then -1 else numeric_precision end attlen,
     c.ordinal_position attnum,
     -1 atttypmod,
-    false attnotnull,
+    case c.is_nullable when 'YES' then false else true end attnotnull,
     false attisdropped,
     false atthasdef
 from information_schema.tables t, information_schema.indexes i, information_schema.columns c
@@ -171,11 +180,13 @@ select
     not non_unique indisunique,
     primary_key indisprimary,
     cast('' as varchar_ignorecase) indexprs,
-    cast(0 as array) indkey
+    cast(1 as array) indkey
 from information_schema.indexes i, information_schema.tables t
 where i.table_schema = t.table_schema
 and i.table_name = t.table_name
-and i.ordinal_position = 1;
+and i.ordinal_position = 1
+-- workaround for MS Access problem opening tables with primary key
+and 1=0;
 
 drop alias if exists pg_get_indexdef;
 create alias pg_get_indexdef for "org.h2.server.pg.PgServer.getIndexColumn";