working on #U4-3876

src/Umbraco.Core/Persistence/SqlSyntax/SqlSyntaxContext.cs

@@ -23,4 +23,24 @@ namespace Umbraco.Core.Persistence.SqlSyntax
             set { _sqlSyntaxProvider = value; }
         }
     }
+
+    internal static class SqlSyntaxProviderExtensions
+    {
+        /// <summary>
+        /// This is used to generate a delete query that uses a sub-query to select the data, it is required because there's a very particular syntax that
+        /// needs to be used to work for all servers: MySql, SQLCE and MSSQL
+        /// </summary>
+        /// <returns></returns>
+        /// <remarks>
+        /// See: http://issues.umbraco.org/issue/U4-3876
+        /// </remarks>
+        public static string GetDeleteSubquery(this ISqlSyntaxProvider sqlProvider, string tableName, string columnName, Sql subQuery)
+        {
+            return string.Format(@"DELETE FROM {0} WHERE {1} IN (SELECT {1} FROM ({2}) x)",
+                                    sqlProvider.GetQuotedTableName(tableName),
+                                    sqlProvider.GetQuotedColumnName(columnName),
+                                    subQuery.SQL);
+        }
+
+    }
 }