[Nhibernate-commit] SF.net SVN: nhibernate:[5543] trunk/nhibernate/src/NHibernate

[<pa...@us...>]

Revision: 5543
          http://nhibernate.svn.sourceforge.net/nhibernate/?rev=5543&view=rev
Author:   patearl
Date:     2011-03-26 18:27:30 +0000 (Sat, 26 Mar 2011)

Log Message:
-----------
Support foreign keys on SQLite.  Breaking change for databases that don't support alter table and have DDL-time foreign key correctness checks.

Modified Paths:
--------------
    trunk/nhibernate/src/NHibernate/Cfg/Configuration.cs
    trunk/nhibernate/src/NHibernate/Dialect/Dialect.cs
    trunk/nhibernate/src/NHibernate/Dialect/SQLiteDialect.cs
    trunk/nhibernate/src/NHibernate/Dialect/Schema/SQLiteMetaData.cs
    trunk/nhibernate/src/NHibernate/Driver/SQLite20Driver.cs
    trunk/nhibernate/src/NHibernate/Mapping/Table.cs

Modified: trunk/nhibernate/src/NHibernate/Cfg/Configuration.cs
===================================================================
--- trunk/nhibernate/src/NHibernate/Cfg/Configuration.cs	2011-03-26 16:35:24 UTC (rev 5542)
+++ trunk/nhibernate/src/NHibernate/Cfg/Configuration.cs	2011-03-26 18:27:30 UTC (rev 5543)
@@ -813,7 +813,10 @@
 
 			var script = new List<string>();
 
-			// drop them in reverse order in case db needs it done that way...
+            if (!string.IsNullOrEmpty(dialect.BeforeDropSchemaCommand))
+                script.Add(dialect.BeforeDropSchemaCommand);
+
+			// drop them in reverse order in case db needs it done that way...););
 			for (int i = auxiliaryDatabaseObjects.Count - 1; i >= 0; i--)
 			{
 				IAuxiliaryDatabaseObject auxDbObj = auxiliaryDatabaseObjects[i];
@@ -861,6 +864,9 @@
 				}
 			}
 
+            if (!string.IsNullOrEmpty(dialect.AfterDropSchemaCommand))
+                script.Add(dialect.AfterDropSchemaCommand);
+
 			return script.ToArray();
 		}
 

Modified: trunk/nhibernate/src/NHibernate/Dialect/Dialect.cs
===================================================================
--- trunk/nhibernate/src/NHibernate/Dialect/Dialect.cs	2011-03-26 16:35:24 UTC (rev 5542)
+++ trunk/nhibernate/src/NHibernate/Dialect/Dialect.cs	2011-03-26 18:27:30 UTC (rev 5543)
@@ -645,7 +645,10 @@
 		{
 			var res = new StringBuilder(200);
 
-			res.Append(" add constraint ")
+            if (SupportsForeignKeyConstraintInAlterTable)
+                res.Append(" add");
+
+			res.Append(" constraint ")
 				.Append(constraintName)
 				.Append(" foreign key (")
 				.Append(StringHelper.Join(StringHelper.CommaSpace, foreignKey))
@@ -2413,5 +2416,15 @@
 		{
 			return false;
 		}
-	}
+
+	    public virtual string BeforeDropSchemaCommand
+	    {
+            get { return null; }
+	    }
+
+        public virtual string AfterDropSchemaCommand
+        {
+            get { return null; }
+        }
+    }
 }

Modified: trunk/nhibernate/src/NHibernate/Dialect/SQLiteDialect.cs
===================================================================
--- trunk/nhibernate/src/NHibernate/Dialect/SQLiteDialect.cs	2011-03-26 16:35:24 UTC (rev 5542)
+++ trunk/nhibernate/src/NHibernate/Dialect/SQLiteDialect.cs	2011-03-26 18:27:30 UTC (rev 5543)
@@ -261,6 +261,23 @@
 			get { return "select randomblob(16)"; }
 		}
 
+        /// <summary>
+        /// SQLite does not currently support dropping foreign key constraints by alter statements.
+        /// This means that tables cannot be dropped if there are any rows that depend on those.
+        /// If there are cycles between tables, it would even be excessively difficult to delete
+        /// the data in the right order first.  Because of this, we just turn off the foreign
+        /// constraints before we drop the schema and hope that we're not going to break anything. :(
+        /// </summary>
+        public override string BeforeDropSchemaCommand
+        {
+            get { return "PRAGMA foreign_keys = OFF"; }
+        }
+
+        public override string AfterDropSchemaCommand
+        {
+            get { return "PRAGMA foreign_keys = ON"; }
+        }
+
 		[Serializable]
 		protected class SQLiteCastFunction : CastFunction
 		{

Modified: trunk/nhibernate/src/NHibernate/Dialect/Schema/SQLiteMetaData.cs
===================================================================
--- trunk/nhibernate/src/NHibernate/Dialect/Schema/SQLiteMetaData.cs	2011-03-26 16:35:24 UTC (rev 5542)
+++ trunk/nhibernate/src/NHibernate/Dialect/Schema/SQLiteMetaData.cs	2011-03-26 18:27:30 UTC (rev 5543)
@@ -30,8 +30,8 @@
 
 		protected override string GetConstraintName(DataRow rs)
 		{
-			throw new NotImplementedException();
-		}
+            return Convert.ToString(rs["CONSTRAINT_NAME"]);
+        }
 
 		protected override IForeignKeyMetadata GetForeignKeyMetadata(DataRow rs)
 		{

Modified: trunk/nhibernate/src/NHibernate/Driver/SQLite20Driver.cs
===================================================================
--- trunk/nhibernate/src/NHibernate/Driver/SQLite20Driver.cs	2011-03-26 16:35:24 UTC (rev 5542)
+++ trunk/nhibernate/src/NHibernate/Driver/SQLite20Driver.cs	2011-03-26 18:27:30 UTC (rev 5543)
@@ -1,4 +1,6 @@
 using System;
+using System.Data;
+using System.Data.Common;
 
 namespace NHibernate.Driver
 {
@@ -33,6 +35,28 @@
 		{
 		}
 
+        public override IDbConnection CreateConnection()
+        {
+            DbConnection connection = (DbConnection)base.CreateConnection();
+            connection.StateChange += Connection_StateChange;
+            return connection;
+        }
+
+        private static void Connection_StateChange(object sender, StateChangeEventArgs e)
+        {
+            if ((e.OriginalState == ConnectionState.Broken || e.OriginalState == ConnectionState.Closed || e.OriginalState == ConnectionState.Connecting) &&
+                e.CurrentState == ConnectionState.Open)
+            {
+                DbConnection connection = (DbConnection)sender;
+                using (DbCommand command = connection.CreateCommand())
+                {
+                    // Activated foreign keys if supported by SQLite.  Unknown pragmas are ignored.
+                    command.CommandText = "PRAGMA foreign_keys = ON";
+                    command.ExecuteNonQuery();
+                }
+            }
+        }
+
 		public override bool UseNamedPrefixInSql
 		{
 			get { return true; }

Modified: trunk/nhibernate/src/NHibernate/Mapping/Table.cs
===================================================================
--- trunk/nhibernate/src/NHibernate/Mapping/Table.cs	2011-03-26 16:35:24 UTC (rev 5542)
+++ trunk/nhibernate/src/NHibernate/Mapping/Table.cs	2011-03-26 18:27:30 UTC (rev 5543)
@@ -427,6 +427,17 @@
 				}
 			}
 
+            if (!dialect.SupportsForeignKeyConstraintInAlterTable)
+            {
+                foreach (ForeignKey foreignKey in ForeignKeyIterator)
+                {
+                    if (foreignKey.HasPhysicalConstraint)
+                    {
+                        buf.Append(",").Append(foreignKey.SqlConstraintString(dialect, foreignKey.Name, defaultCatalog, defaultSchema));
+                    }
+                }
+            }
+
 			buf.Append(StringHelper.ClosedParen);
 
 			if (string.IsNullOrEmpty(comment) == false)


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