MDEV-7280 DATABASE: CREATE OR REPLACE

mysql-test/r/create_drop_binlog.result

+CREATE OR REPLACE DATABASE d1;
+CREATE OR REPLACE DATABASE d1;
+DROP DATABASE d1;
+CREATE DATABASE IF NOT EXISTS d1;
+CREATE DATABASE IF NOT EXISTS d1;
+Warnings:
+Note	1007	Can't create database 'd1'; database exists
+DROP DATABASE IF EXISTS d1;
+DROP DATABASE IF EXISTS d1;
+Warnings:
+Note	1008	Can't drop database 'd1'; database doesn't exist
+"Runnig SHOW BINLOG EVENTS"
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+#	#	Gtid	1	#	GTID #-#-#
+#	#	Query	1	#	CREATE OR REPLACE DATABASE d1
+#	#	Gtid	1	#	GTID #-#-#
+#	#	Query	1	#	CREATE OR REPLACE DATABASE d1
+#	#	Gtid	1	#	GTID #-#-#
+#	#	Query	1	#	DROP DATABASE d1
+#	#	Gtid	1	#	GTID #-#-#
+#	#	Query	1	#	CREATE DATABASE IF NOT EXISTS d1
+#	#	Gtid	1	#	GTID #-#-#
+#	#	Query	1	#	CREATE DATABASE IF NOT EXISTS d1
+#	#	Gtid	1	#	GTID #-#-#
+#	#	Query	1	#	DROP DATABASE IF EXISTS d1
+#	#	Gtid	1	#	GTID #-#-#
+#	#	Query	1	#	DROP DATABASE IF EXISTS d1
+RESET MASTER;
+USE test;

mysql-test/r/create_drop_db.result

+CREATE DATABASE IF NOT EXISTS db1;
+affected rows: 1
+CREATE DATABASE IF NOT EXISTS db1;
+affected rows: 0
+Warnings:
+Note	1007	Can't create database 'db1'; database exists
+CREATE TABLE db1.t1 (a INT);
+affected rows: 0
+SHOW TABLES IN db1;
+Tables_in_db1
+t1
+affected rows: 1
+CREATE OR REPLACE DATABASE db1;
+affected rows: 2
+SHOW TABLES IN db1;
+Tables_in_db1
+affected rows: 0
+CREATE OR REPLACE DATABASE IF NOT EXISTS db2;
+ERROR HY000: Incorrect usage of OR REPLACE and IF NOT EXISTS
+DROP DATABASE db1;
+affected rows: 0
+DROP DATABASE IF EXISTS db1;
+affected rows: 0
+Warnings:
+Note	1008	Can't drop database 'db1'; database doesn't exist
+DROP DATABASE db1;
+ERROR HY000: Can't drop database 'db1'; database doesn't exist
+CREATE OR REPLACE DATABASE db1;
+affected rows: 1
+SHOW TABLES IN db1;
+Tables_in_db1
+affected rows: 0
+CREATE DATABASE db1;
+ERROR HY000: Can't create database 'db1'; database exists
+DROP DATABASE IF EXISTS db1;
+affected rows: 0
+DROP DATABASE IF EXISTS db1;
+affected rows: 0
+Warnings:
+Note	1008	Can't drop database 'db1'; database doesn't exist

mysql-test/suite/rpl/r/rpl_create_drop_db.result

+include/master-slave.inc
+[connection master]
+CREATE DATABASE db1;
+CREATE DATABASE IF NOT EXISTS db1;
+Warnings:
+Note	1007	Can't create database 'db1'; database exists
+CREATE OR REPLACE DATABASE db2;
+CREATE OR REPLACE DATABASE db1;
+SHOW DATABASES;
+Database
+db1
+db2
+information_schema
+mtr
+mysql
+performance_schema
+test
+CREATE DATABASE db1;
+ERROR HY000: Can't create database 'db1'; database exists
+DROP DATABASE db3;
+ERROR HY000: Can't drop database 'db3'; database doesn't exist
+CREATE DATABASE IF NOT EXISTS db3;
+SHOW DATABASES;
+Database
+db1
+db2
+db3
+information_schema
+mtr
+mysql
+performance_schema
+test
+DROP DATABASE db1;
+DROP DATABASE db2;
+DROP DATABASE IF EXISTS db3;
+SHOW DATABASES;
+Database
+information_schema
+mtr
+mysql
+performance_schema
+test
+include/rpl_end.inc

mysql-test/suite/rpl/t/rpl_create_drop_db.test

+--source include/master-slave.inc
+
+connection master;
+
+CREATE DATABASE db1;
+CREATE DATABASE IF NOT EXISTS db1;
+CREATE OR REPLACE DATABASE db2;
+CREATE OR REPLACE DATABASE db1;
+sync_slave_with_master;
+
+SHOW DATABASES;
+
+connection master;
+--error ER_DB_CREATE_EXISTS
+CREATE DATABASE db1;
+
+--error ER_DB_DROP_EXISTS
+DROP DATABASE db3;
+
+CREATE DATABASE IF NOT EXISTS db3;
+sync_slave_with_master;
+
+SHOW DATABASES;
+
+connection master;
+DROP DATABASE db1;
+DROP DATABASE db2;
+DROP DATABASE IF EXISTS db3;
+sync_slave_with_master;
+
+SHOW DATABASES;
+
+--source include/rpl_end.inc

mysql-test/t/create_drop_binlog.test

+--source include/have_log_bin.inc
+
+--let $binlog_file=query_get_value(SHOW MASTER STATUS, File, 1)
+--let $binlog_start=query_get_value(SHOW MASTER STATUS, Position, 1)
+
+CREATE OR REPLACE DATABASE d1;
+CREATE OR REPLACE DATABASE d1;
+DROP DATABASE d1;
+CREATE DATABASE IF NOT EXISTS d1;
+CREATE DATABASE IF NOT EXISTS d1;
+DROP DATABASE IF EXISTS d1;
+DROP DATABASE IF EXISTS d1;
+--echo "Runnig SHOW BINLOG EVENTS"
+--replace_column 1 # 2 # 5 #
+--replace_regex /xid=[0-9]+/xid=XX/ /GTID [0-9]+-[0-9]+-[0-9]+/GTID #-#-#/ /Server.ver.*/VERSIONS/
+--disable_query_log
+--eval SHOW BINLOG EVENTS FROM $binlog_start;
+--enable_query_log
+RESET MASTER;
+USE test;

mysql-test/t/create_drop_db.test

+# Enable diisplaying rows affected
+--enable_info
+
+CREATE DATABASE IF NOT EXISTS db1;
+
+CREATE DATABASE IF NOT EXISTS db1;
+CREATE TABLE db1.t1 (a INT);
+SHOW TABLES IN db1;
+
+CREATE OR REPLACE DATABASE db1;
+SHOW TABLES IN db1;
+
+--error ER_WRONG_USAGE
+CREATE OR REPLACE DATABASE IF NOT EXISTS db2;
+
+DROP DATABASE db1;
+
+DROP DATABASE IF EXISTS db1;
+
+--error ER_DB_DROP_EXISTS
+DROP DATABASE db1;
+
+CREATE OR REPLACE DATABASE db1;
+SHOW TABLES IN db1;
+
+--error ER_DB_CREATE_EXISTS
+CREATE DATABASE db1;
+
+DROP DATABASE IF EXISTS db1;
+DROP DATABASE IF EXISTS db1;
+
+--disable_info

sql/sql_db.cc

@@ -62,6 +62,8 @@ static void mysql_change_db_impl(THD *thd,
                                  LEX_STRING *new_db_name,
                                  ulong new_db_access,
                                  CHARSET_INFO *new_db_charset);
+static bool mysql_rm_db_internal(THD *thd, char *db,
+                                 bool if_exists, bool silent);
 
 
 /* Database options hash */
@@ -542,7 +544,7 @@ CHARSET_INFO *get_default_db_collation(THD *thd, const char *db_name)
   Create a database
 
   SYNOPSIS
-  mysql_create_db()
+  mysql_create_db_iternal()
   thd		Thread handler
   db		Name of database to create
 		Function assumes that this is already validated.
@@ -563,14 +565,13 @@ CHARSET_INFO *get_default_db_collation(THD *thd, const char *db_name)
 
 */
 
-int mysql_create_db(THD *thd, char *db,
-                    const DDL_options_st &options,
-                    Schema_specification_st *create_info,
-                    bool silent)
+static int
+mysql_create_db_internal(THD *thd, char *db,
+                         const DDL_options_st &options,
+                         Schema_specification_st *create_info,
+                         bool silent)
 {
   char	 path[FN_REFLEN+16];
-  long result= 1;
-  int error= 0;
   MY_STAT stat_info;
   uint path_len;
   DBUG_ENTER("mysql_create_db");
@@ -599,32 +600,45 @@ int mysql_create_db(THD *thd, char *db,
   path_len= build_table_filename(path, sizeof(path) - 1, db, "", "", 0);
   path[path_len-1]= 0;                    // Remove last '/' from path
 
-  if (mysql_file_stat(key_file_misc, path, &stat_info, MYF(0)))
+  long affected_rows= 1;
+  if (!mysql_file_stat(key_file_misc, path, &stat_info, MYF(0)))
   {
-    if (!options.if_not_exists())
+    // The database directory does not exist, or my_file_stat() failed
+    if (my_errno != ENOENT)
     {
-      my_error(ER_DB_CREATE_EXISTS, MYF(0), db);
-      error= -1;
-      goto exit;
+      my_error(EE_STAT, MYF(0), path, my_errno);
+      DBUG_RETURN(1);
     }
+  }
+  else if (options.or_replace())
+  {
+    if (mysql_rm_db_internal(thd, db, 0, true)) // Removing the old database
+      DBUG_RETURN(1);
+    /*
+      Reset the diagnostics m_status.
+      It might be set ot DA_OK in mysql_rm_db.
+    */
+    thd->get_stmt_da()->reset_diagnostics_area();
+    affected_rows= 2;
+  }
+  else if (options.if_not_exists())
+  {
     push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
-			ER_DB_CREATE_EXISTS, ER(ER_DB_CREATE_EXISTS), db);
-    error= 0;
+                      ER_DB_CREATE_EXISTS, ER(ER_DB_CREATE_EXISTS), db);
+    affected_rows= 0;
     goto not_silent;
   }
   else
   {
-    if (my_errno != ENOENT)
-    {
-      my_error(EE_STAT, MYF(0), path, my_errno);
-      goto exit;
-    }
-    if (my_mkdir(path,0777,MYF(0)) < 0)
-    {
-      my_error(ER_CANT_CREATE_DB, MYF(0), db, my_errno);
-      error= -1;
-      goto exit;
-    }
+    my_error(ER_DB_CREATE_EXISTS, MYF(0), db);
+    DBUG_RETURN(-1);
+  }
+
+
+  if (my_mkdir(path, 0777, MYF(0)) < 0)
+  {
+    my_error(ER_CANT_CREATE_DB, MYF(0), db, my_errno);
+    DBUG_RETURN(-1);
   }
 
   path[path_len-1]= FN_LIBCHAR;
@@ -637,10 +651,7 @@ int mysql_create_db(THD *thd, char *db,
     */
     path[path_len]= 0;
     if (rmdir(path) >= 0)
-    {
-      error= -1;
-      goto exit;
-    }
+      DBUG_RETURN(-1);
     /*
       We come here when we managed to create the database, but not the option
       file.  In this case it's best to just continue as if nothing has
@@ -690,23 +701,20 @@ int mysql_create_db(THD *thd, char *db,
         metadata lock on the schema
       */
       if (mysql_bin_log.write(&qinfo))
-      {
-        error= -1;
-        goto exit;
-      }
+        DBUG_RETURN(-1);
     }
-    my_ok(thd, result);
+    my_ok(thd, affected_rows);
   }
 
-exit:
-  DBUG_RETURN(error);
+  DBUG_RETURN(0);
 }
 
 
 /* db-name is already validated when we come here */
 
-bool mysql_alter_db(THD *thd, const char *db,
-                    Schema_specification_st *create_info)
+static bool
+mysql_alter_db_internal(THD *thd, const char *db,
+                        Schema_specification_st *create_info)
 {
   char path[FN_REFLEN+16];
   long result=1;
@@ -762,6 +770,31 @@ bool mysql_alter_db(THD *thd, const char *db,
 }
 
 
+int mysql_create_db(THD *thd, char *db,
+                    const DDL_options_st &options,
+                    const Schema_specification_st *create_info)
+{
+  /*
+    As mysql_create_db_internal() may modify Db_create_info structure passed
+    to it, we need to use a copy to make execution prepared statement- safe.
+  */
+  Schema_specification_st tmp(*create_info);
+  return mysql_create_db_internal(thd, db, options, &tmp, false);
+}
+
+
+bool mysql_alter_db(THD *thd, const char *db,
+                    const Schema_specification_st *create_info)
+{
+  /*
+    As mysql_alter_db_internal() may modify Db_create_info structure passed
+    to it, we need to use a copy to make execution prepared statement- safe.
+  */
+  Schema_specification_st tmp(*create_info);
+  return mysql_alter_db_internal(thd, db, &tmp);
+}
+
+
 /**
   Drop all tables, routines and events in a database and the database itself.
 
@@ -777,7 +810,8 @@ bool mysql_alter_db(THD *thd, const char *db,
   @retval  true   Error
 */
 
-bool mysql_rm_db(THD *thd,char *db, bool if_exists, bool silent)
+static bool
+mysql_rm_db_internal(THD *thd,char *db, bool if_exists, bool silent)
 {
   ulong deleted_tables= 0;
   bool error= true;
@@ -1004,6 +1038,12 @@ bool mysql_rm_db(THD *thd,char *db, bool if_exists, bool silent)
 }
 
 
+bool mysql_rm_db(THD *thd,char *db, bool if_exists)
+{
+  return mysql_rm_db_internal(thd, db, if_exists, false);
+}
+
+
 static bool find_db_tables_and_rm_known_files(THD *thd, MY_DIR *dirp,
                                               char *dbname,
                                               const char *path,
@@ -1654,7 +1694,8 @@ bool mysql_upgrade_db(THD *thd, LEX_STRING *old_db)
   }
 
   /* Step1: Create the new database */
-  if ((error= mysql_create_db(thd, new_db.str, DDL_options(), &create_info, 1)))
+  if ((error= mysql_create_db_internal(thd, new_db.str,
+                                       DDL_options(), &create_info, 1)))
     goto exit;
 
   /* Step2: Move tables to the new database */
@@ -1778,7 +1819,7 @@ bool mysql_upgrade_db(THD *thd, LEX_STRING *old_db)
     to execute them again.
     mysql_rm_db() also "unuses" if we drop the current database.
   */
-  error= mysql_rm_db(thd, old_db->str, 0, 1);
+  error= mysql_rm_db_internal(thd, old_db->str, 0, true);
 
   /* Step8: logging */
   if (mysql_bin_log.is_open())

sql/sql_db.h

@@ -22,10 +22,10 @@ class THD;
 
 int mysql_create_db(THD *thd, char *db,
                     const DDL_options_st &options,
-                    Schema_specification_st *create, bool silent);
+                    const Schema_specification_st *create);
 bool mysql_alter_db(THD *thd, const char *db,
-                    Schema_specification_st *create);
-bool mysql_rm_db(THD *thd, char *db, bool if_exists, bool silent);
+                    const Schema_specification_st *create);
+bool mysql_rm_db(THD *thd, char *db, bool if_exists);
 bool mysql_upgrade_db(THD *thd, LEX_STRING *old_db);
 bool mysql_change_db(THD *thd, const LEX_STRING *new_db_name,
                      bool force_switch);

sql/sql_parse.cc

@@ -4301,7 +4301,7 @@ mysql_execute_command(THD *thd)
     if (check_access(thd, CREATE_ACL, lex->name.str, NULL, NULL, 1, 0))
       break;
     WSREP_TO_ISOLATION_BEGIN(lex->name.str, NULL, NULL)
-    res= mysql_create_db(thd, lex->name.str, lex->create_info, &create_info, 0);
+    res= mysql_create_db(thd, lex->name.str, lex->create_info, &create_info);
     break;
   }
   case SQLCOM_DROP_DB:
@@ -4333,7 +4333,7 @@ mysql_execute_command(THD *thd)
     if (check_access(thd, DROP_ACL, lex->name.str, NULL, NULL, 1, 0))
       break;
     WSREP_TO_ISOLATION_BEGIN(lex->name.str, NULL, NULL)
-    res= mysql_rm_db(thd, lex->name.str, lex->if_exists(), 0);
+    res= mysql_rm_db(thd, lex->name.str, lex->if_exists());
     break;
   }
   case SQLCOM_ALTER_DB_UPGRADE:

sql/sql_yacc.yy

@@ -2538,7 +2538,7 @@ create:
               MYSQL_YYABORT;
           }
           opt_index_lock_algorithm { }
-        | CREATE DATABASE opt_if_not_exists ident
+        | create_or_replace DATABASE opt_if_not_exists ident
           {
             Lex->create_info.default_table_charset= NULL;
             Lex->create_info.used_fields= 0;
@@ -2546,7 +2546,8 @@ create:
           opt_create_database_options
           {
             LEX *lex=Lex;
-            lex->set_command(SQLCOM_CREATE_DB, $3);
+            if (lex->set_command_with_check(SQLCOM_CREATE_DB, 0, $1 | $3))
+               MYSQL_YYABORT;
             lex->name= $4;
           }
         | create_or_replace