From a6630dff5bf2002c0c133ea6c5e16d8a0a22138f Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Fri, 11 Mar 2011 14:21:52 +0200
Subject: Create indexes in separate SQL statements

This is more vendor-neutral.
---
 odb/relational/mysql/schema.cxx |  2 +-
 odb/relational/schema.cxx       |  5 +--
 odb/relational/schema.hxx       | 76 +++++++++++++++++++++++++++--------------
 odb/relational/source.hxx       |  7 ++--
 4 files changed, 59 insertions(+), 31 deletions(-)

diff --git a/odb/relational/mysql/schema.cxx b/odb/relational/mysql/schema.cxx
index 37f3412..0b44c53 100644
--- a/odb/relational/mysql/schema.cxx
+++ b/odb/relational/mysql/schema.cxx
@@ -23,7 +23,7 @@ namespace relational
       struct create_common: virtual relational::create_common
       {
         virtual void
-        create_post ()
+        create_table_post ()
         {
           os << ")";
 
diff --git a/odb/relational/schema.cxx b/odb/relational/schema.cxx
index 0836e03..6afdb32 100644
--- a/odb/relational/schema.cxx
+++ b/odb/relational/schema.cxx
@@ -36,8 +36,9 @@ namespace relational
       virtual void
       post ()
       {
-        os << ';' << endl
-           << endl;
+        if (!first_) // Ignore empty statements.
+          os << ';' << endl
+             << endl;
       }
 
     private:
diff --git a/odb/relational/schema.hxx b/odb/relational/schema.hxx
index 9da6624..6c481da 100644
--- a/odb/relational/schema.hxx
+++ b/odb/relational/schema.hxx
@@ -50,10 +50,20 @@ namespace relational
     struct drop_common: virtual context
     {
       virtual void
-      drop (string const& table)
+      drop_table (string const& table)
       {
         os << "DROP TABLE IF EXISTS " << quote_id (table) << endl;
       }
+
+      virtual void
+      drop_index (string const& /*table*/, string const& /*column*/)
+      {
+        // Most database systems drop indexes together with the table.
+        //
+
+        //os << "DROP INDEX IF EXISTS " << quote_id (table + '_' + column)
+        //   << endl;
+      }
     };
 
     struct member_drop: object_members_base, common, virtual drop_common
@@ -78,11 +88,26 @@ namespace relational
         if (tables_.count (name))
           return;
 
+        // Drop table.
+        //
         pre_statement ();
-        drop (name);
+        drop_table (name);
         post_statement ();
 
         tables_.insert (name);
+
+        // Drop indexes.
+        //
+        pre_statement ();
+        drop_index (name, column_name (m, "id", "object_id"));
+        post_statement ();
+
+        if (container_kind (m.type ()) == ck_ordered && !unordered (m))
+        {
+          pre_statement ();
+          drop_index (name, column_name (m, "index", "index"));
+          post_statement ();
+        }
       }
 
     protected:
@@ -120,7 +145,7 @@ namespace relational
           return;
 
         pre_statement ();
-        drop (name);
+        drop_table (name);
         post_statement ();
 
         tables_.insert (name);
@@ -187,25 +212,26 @@ namespace relational
     struct create_common: virtual context
     {
       virtual void
-      create_pre (string const& table)
+      create_table_pre (string const& table)
       {
         os << "CREATE TABLE " << quote_id (table) << " (" << endl;
       }
 
       virtual void
-      index (string const& column)
+      create_table_post ()
       {
-        os << "INDEX (" << quote_id (column) << ")";
+        os << ")" << endl;
       }
 
       virtual void
-      create_post ()
+      create_index (string const& table, string const& column)
       {
-        os << ")" << endl;
+        os << "CREATE INDEX " << quote_id (table + '_' + column) << endl
+           << "  ON " << quote_id (table) << " (" << quote_id (column) << ")"
+           << endl;
       }
     };
 
-
     struct member_create: object_members_base, common, virtual create_common
     {
       typedef member_create base;
@@ -236,7 +262,7 @@ namespace relational
           return;
 
         pre_statement ();
-        create_pre (name);
+        create_table_pre (name);
 
         // object_id (simple value)
         //
@@ -298,25 +324,23 @@ namespace relational
           }
         }
 
-        // object_id index
-        //
-        os << "," << endl
-           << "  ";
-        index (id_name);
+        create_table_post ();
+        post_statement ();
+
+        tables_.insert (name);
 
-        // index index
+        // Create indexes.
         //
+        pre_statement ();
+        create_index (name, id_name);
+        post_statement ();
+
         if (ordered)
         {
-          os << "," << endl
-             << "  ";
-          index (index_name);
+          pre_statement ();
+          create_index (name, index_name);
+          post_statement ();
         }
-
-        create_post ();
-        post_statement ();
-
-        tables_.insert (name);
       }
 
     protected:
@@ -357,14 +381,14 @@ namespace relational
           return;
 
         pre_statement ();
-        create_pre (name);
+        create_table_pre (name);
 
         {
           instance<object_columns> oc;
           oc->traverse (c);
         }
 
-        create_post ();
+        create_table_post ();
         post_statement ();
 
         tables_.insert (name);
diff --git a/odb/relational/source.hxx b/odb/relational/source.hxx
index 37dfa27..106bf27 100644
--- a/odb/relational/source.hxx
+++ b/odb/relational/source.hxx
@@ -27,14 +27,16 @@ namespace relational
       pre ()
       {
         first_ = true;
-        os << "db.execute (";
       }
 
       virtual void
       line (const std::string& l)
       {
         if (first_)
+        {
           first_ = false;
+          os << "db.execute (";
+        }
         else
           os << endl;
 
@@ -44,7 +46,8 @@ namespace relational
       virtual void
       post ()
       {
-        os << ");" << endl;
+        if (!first_) // Ignore empty statements.
+          os << ");" << endl;
       }
 
     private:
-- 
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