[OPENJPA-282] Postgresql does not support deferred unique constraints.

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 1.0.1, 1.1.0
• Component/s: jdbc
• Environment: PostgreSQL
• Assignee: Unassigned
• Reporter: Daniel Migowski
• Created: 09/Jul/07 15:59
• Updated: 09/Mar/10 18:32
• Resolved: 28/Aug/07 21:51

Description

PostgreSQL does not support deferred unique constraints. Since the dictionary states deferred constraints capabilities, this results in an error on automatic database generation for unique fields.

Oh, and identifiers can be 63 chars long... not 31(since at least postgres 7.3, which has last be updated 2005, and is outdated by 7.4 since 2000).

Please use the attached patch to fix this. (Or try something else... . Maybe one could better define a variable to describe this capability.

With best regards,
Daniel Migowski

--------------------- PATCH BEGINS BELOW THIS LINE --------------------------
Index: C:/IKOfficeRoot/Projekte/OpenJPA/openjpa/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/PostgresDictionary.java
===================================================================
— C:/IKOfficeRoot/Projekte/OpenJPA/openjpa/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/PostgresDictionary.java (revision 554663)
+++ C:/IKOfficeRoot/Projekte/OpenJPA/openjpa/openjpa-jdbc/src/main/java/org/apache/openjpa/jdbc/sql/PostgresDictionary.java (working copy)
@@ -32,6 +32,7 @@
import org.apache.openjpa.jdbc.schema.Column;
import org.apache.openjpa.jdbc.schema.Sequence;
import org.apache.openjpa.jdbc.schema.Table;
+import org.apache.openjpa.jdbc.schema.Unique;
import org.apache.openjpa.lib.jdbc.DelegatingConnection;
import org.apache.openjpa.lib.jdbc.DelegatingPreparedStatement;
import org.apache.openjpa.lib.util.Localizer;
@@ -36,6 +37,8 @@
import org.apache.openjpa.lib.jdbc.DelegatingPreparedStatement;
import org.apache.openjpa.lib.util.Localizer;

+import serp.util.Strings;
+
/**

• Dictionary for Postgres.
  */
  @@ -93,10 +96,10 @@
  // PostgreSQL requires double-escape for strings
  searchStringEscape = "\\\\";

• maxTableNameLength = 31;
• maxColumnNameLength = 31;
• maxIndexNameLength = 31;
• maxConstraintNameLength = 31;
  + maxTableNameLength = 63;
  + maxColumnNameLength = 63;
  + maxIndexNameLength = 63;
  + maxConstraintNameLength = 63;
  schemaCase = SCHEMA_CASE_LOWER;
  rangePosition = RANGE_POST_LOCK;
  requiresAliasForSubselect = true;
  @@ -301,6 +304,31 @@
  throws SQLException { return new PostgresConnection(super.decorate(conn), this); }

  +
  + /**
  + * Return the declaration SQL for the given unique constraint. This
  + * method is used from within

  {@link #getCreateTableSQL}

  .
  + * Returns <code>CONSTRAINT <name> UNIQUE (<col list>)</code>
  + * by default. Only foreign key constraints can be deferred in PostgreSQL
  + * so we have to override the function in DbDictionary.
  + */
  + protected String getUniqueConstraintSQL(Unique unq)

  { + if (unq.isDeferred()) return null; + + StringBuffer buf = new StringBuffer(); + if (unq.getName() != null + && CONS_NAME_BEFORE.equals(constraintNameMode)) + buf.append("CONSTRAINT ").append(unq.getName()).append(" "); + buf.append("UNIQUE "); + if (unq.getName() != null && CONS_NAME_MID.equals(constraintNameMode)) + buf.append(unq.getName()).append(" "); + buf.append("(").append(Strings.join(unq.getColumns(), ", ")). + append(")"); + if (unq.getName() != null + && CONS_NAME_AFTER.equals(constraintNameMode)) + buf.append(" CONSTRAINT ").append(unq.getName()); + return buf.toString(); + }

/**

• Connection wrapper to work around the postgres empty result set bug.

Issue Links

• is duplicated by: OPENJPA-426 Incorrect DEFERRABLE usage with PostgreSQL