MDEV-7285 SERVER: CREATE OR REPLACE and CREATE IF NOT EXISTS

mysql-test/r/create_drop_binlog.result

@@ -27,6 +27,24 @@ Log_name	Pos	Event_type	Server_id	End_log_pos	Info
 #	#	Query	1	#	DROP DATABASE IF EXISTS d1
 RESET MASTER;
 USE test;
+#
+# CREATE SERVER is not logged
+#
+CREATE OR REPLACE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+CREATE OR REPLACE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+DROP SERVER s1;
+CREATE SERVER IF NOT EXISTS s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+CREATE SERVER IF NOT EXISTS s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+Warnings:
+Note	1476	The foreign server, s1, you are trying to create already exists.
+DROP SERVER IF EXISTS s1;
+DROP SERVER IF EXISTS s1;
+SHOW BINLOG EVENTS;
+Log_name	Pos	Event_type	Server_id	End_log_pos	Info
+#	#	Format_desc	1	#	VER
+#	#	Gtid_list	1	#	[]
+#	#	Binlog_checkpoint	1	#	master-bin.000001
+RESET MASTER;
 CREATE OR REPLACE VIEW v1 AS SELECT 1;
 CREATE OR REPLACE VIEW v1 AS SELECT 1;
 DROP VIEW v1;

mysql-test/r/create_drop_server.result

@@ -0,0 +1,37 @@
+#
+# MDEV-7285 SERVER: CREATE OR REPLACE and CREATE IF NOT EXISTS
+#
+CREATE SERVER IF NOT EXISTS server1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'user1', HOST 'localhost', DATABASE 'test0');
+SELECT server_name, username, db FROM mysql.servers;
+server_name	username	db
+server1	user1	test0
+CREATE SERVER IF NOT EXISTS server1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'user2', HOST 'localhost', DATABASE 'test1');
+Warnings:
+Note	1476	The foreign server, server1, you are trying to create already exists.
+SELECT server_name, username, db FROM mysql.servers;
+server_name	username	db
+server1	user1	test0
+CREATE OR REPLACE SERVER server1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'user3', HOST 'localhost', DATABASE 'test2');
+SELECT server_name, username, db FROM mysql.servers;
+server_name	username	db
+server1	user3	test2
+DROP SERVER IF EXISTS server1;
+SELECT server_name, username, db FROM mysql.servers;
+server_name	username	db
+DROP SERVER IF EXISTS server1;
+CREATE SERVER server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test0');
+CREATE SERVER server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test1');
+ERROR HY000: The foreign server, server_1, you are trying to create already exists.
+CREATE SERVER IF NOT EXISTS server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test2');
+Warnings:
+Note	1476	The foreign server, server_1, you are trying to create already exists.
+SELECT server_name, username, db FROM mysql.servers;
+server_name	username	db
+server_1	mysqltest_1	test0
+CREATE OR REPLACE SERVER IF NOT EXISTS server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test3');
+ERROR HY000: Incorrect usage of OR REPLACE and IF NOT EXISTS
+CREATE OR REPLACE SERVER server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test4');
+SELECT server_name, username, db FROM mysql.servers;
+server_name	username	db
+server_1	mysqltest_1	test4
+DROP SERVER server_1;

mysql-test/t/create_drop_binlog.test

@@ -19,6 +19,22 @@ DROP DATABASE IF EXISTS d1;
 RESET MASTER;
 USE test;
 
+--echo #
+--echo # CREATE SERVER is not logged
+--echo #
+CREATE OR REPLACE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+CREATE OR REPLACE SERVER s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+DROP SERVER s1;
+CREATE SERVER IF NOT EXISTS s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+CREATE SERVER IF NOT EXISTS s1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'root', HOST 'localhost', DATABASE 'test');
+DROP SERVER IF EXISTS s1;
+DROP SERVER IF EXISTS s1;
+--replace_column 1 # 2 # 5 #
+--replace_regex /xid=[0-9]+/xid=XX/ /GTID [0-9]+-[0-9]+-[0-9]+/GTID #-#-#/ /Server.ver.*/VER/
+SHOW BINLOG EVENTS;
+RESET MASTER;
+
+
 
 CREATE OR REPLACE VIEW v1 AS SELECT 1;
 CREATE OR REPLACE VIEW v1 AS SELECT 1;

mysql-test/t/create_drop_server.test

@@ -0,0 +1,25 @@
+--echo #
+--echo # MDEV-7285 SERVER: CREATE OR REPLACE and CREATE IF NOT EXISTS
+--echo #
+
+CREATE SERVER IF NOT EXISTS server1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'user1', HOST 'localhost', DATABASE 'test0');
+SELECT server_name, username, db FROM mysql.servers;
+CREATE SERVER IF NOT EXISTS server1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'user2', HOST 'localhost', DATABASE 'test1');
+SELECT server_name, username, db FROM mysql.servers;
+CREATE OR REPLACE SERVER server1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'user3', HOST 'localhost', DATABASE 'test2');
+SELECT server_name, username, db FROM mysql.servers;
+DROP SERVER IF EXISTS server1;
+SELECT server_name, username, db FROM mysql.servers;
+DROP SERVER IF EXISTS server1;
+
+
+CREATE SERVER server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test0');
+--error ER_FOREIGN_SERVER_EXISTS
+CREATE SERVER server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test1');
+CREATE SERVER IF NOT EXISTS server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test2');
+SELECT server_name, username, db FROM mysql.servers;
+--error ER_WRONG_USAGE
+CREATE OR REPLACE SERVER IF NOT EXISTS server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test3');
+CREATE OR REPLACE SERVER server_1 FOREIGN DATA WRAPPER mysql OPTIONS (USER 'mysqltest_1', HOST 'localhost', DATABASE 'test4');
+SELECT server_name, username, db FROM mysql.servers;
+DROP SERVER server_1;

sql/sql_parse.cc

@@ -5446,21 +5446,13 @@ mysql_execute_command(THD *thd)
   }
   case SQLCOM_CREATE_SERVER:
   {
-    int error;
     LEX *lex= thd->lex;
     DBUG_PRINT("info", ("case SQLCOM_CREATE_SERVER"));
 
     if (check_global_access(thd, SUPER_ACL))
       break;
 
-    if ((error= create_server(thd, &lex->server_options)))
-    {
-      DBUG_PRINT("info", ("problem creating server <%s>",
-                          lex->server_options.server_name.str));
-      my_error(error, MYF(0), lex->server_options.server_name.str);
-      break;
-    }
-    my_ok(thd, 1);
+    res= create_server(thd, &lex->server_options);
     break;
   }
   case SQLCOM_ALTER_SERVER:

sql/sql_servers.cc

@@ -582,8 +582,8 @@ int insert_server_record(TABLE *table, FOREIGN_SERVER *server)
     This function takes as its arguments a THD object pointer and a pointer
     to a LEX_SERVER_OPTIONS struct from the parser. The member 'server_name'
     of this LEX_SERVER_OPTIONS struct contains the value of the server to be
-    deleted. The mysql.servers table is opened via open_ltable, a table object
-    returned, the servers cache mutex locked, then delete_server_record is
+    deleted. The mysql.servers table is opened via open_ltable,
+    a table object returned, then delete_server_record is
     called with this table object and LEX_SERVER_OPTIONS server_name and
     server_name_length passed, containing the name of the server to be
     dropped/deleted, then delete_server_record_in_cache is called to delete
@@ -594,20 +594,18 @@ int insert_server_record(TABLE *table, FOREIGN_SERVER *server)
     > 0 - error code
 */
 
-int drop_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
+static int drop_server_internal(THD *thd, LEX_SERVER_OPTIONS *server_options)
 {
   int error;
   TABLE_LIST tables;
   TABLE *table;
 
-  DBUG_ENTER("drop_server");
+  DBUG_ENTER("drop_server_internal");
   DBUG_PRINT("info", ("server name server->server_name %s",
                       server_options->server_name.str));
 
   tables.init_one_table("mysql", 5, "servers", 7, "servers", TL_WRITE);
 
-  mysql_rwlock_wrlock(&THR_LOCK_servers);
-
   /* hit the memory hit first */
   if ((error= delete_server_record_in_cache(server_options)))
     goto end;
@@ -630,11 +628,22 @@ int drop_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
   }
 
 end:
-  mysql_rwlock_unlock(&THR_LOCK_servers);
   DBUG_RETURN(error);
 }
 
 
+/**
+  Drop a server with servers cache mutex lock.
+*/
+int drop_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
+{
+  mysql_rwlock_wrlock(&THR_LOCK_servers);
+  int rc= drop_server_internal(thd, server_options);
+  mysql_rwlock_unlock(&THR_LOCK_servers);
+  return rc;
+}
+
+
 /*
 
   SYNOPSIS
@@ -989,8 +998,24 @@ int create_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
   /* hit the memory first */
   if (my_hash_search(&servers_cache, (uchar*) server_options->server_name.str,
                      server_options->server_name.length))
-    goto end;
-
+  {
+    if (thd->lex->create_info.or_replace())
+    {
+      if ((error= drop_server_internal(thd, server_options)))
+        goto end;
+    }
+    else if (thd->lex->create_info.if_not_exists())
+    {
+      push_warning_printf(thd, Sql_condition::WARN_LEVEL_NOTE,
+                          ER_FOREIGN_SERVER_EXISTS,
+                          ER(ER_FOREIGN_SERVER_EXISTS),
+                          server_options->server_name.str);
+      error= 0;
+      goto end;
+    }
+    else
+      goto end;
+  }
 
   if (!(server= prepare_server_struct_for_insert(server_options)))
   {
@@ -1006,6 +1031,16 @@ int create_server(THD *thd, LEX_SERVER_OPTIONS *server_options)
 
 end:
   mysql_rwlock_unlock(&THR_LOCK_servers);
+
+  if (error)
+  {
+    DBUG_PRINT("info", ("problem creating server <%s>",
+                        server_options->server_name.str));
+    my_error(error, MYF(0), server_options->server_name.str);
+  }
+  else
+    my_ok(thd);
+
   DBUG_RETURN(error);
 }
 

sql/sql_yacc.yy

@@ -2584,18 +2584,21 @@ create:
           {
             Lex->alter_tablespace_info->ts_cmd_type= CREATE_TABLESPACE;
           }
-        | CREATE server_def
-          {
-            Lex->sql_command= SQLCOM_CREATE_SERVER;
-          }
+        | create_or_replace { Lex->set_command(SQLCOM_CREATE_SERVER, $1); }
+          server_def
+          { }
         ;
 
 server_def:
-          SERVER_SYM ident_or_text
-          { Lex->server_options.reset($2); }
+          SERVER_SYM opt_if_not_exists ident_or_text
+          {
+            if (Lex->add_create_options_with_check($2))
+              MYSQL_YYABORT;
+            Lex->server_options.reset($3);
+          }
           FOREIGN DATA_SYM WRAPPER_SYM ident_or_text
           OPTIONS_SYM '(' server_options_list ')'
-          { Lex->server_options.scheme= $7; }
+          { Lex->server_options.scheme= $8; }
         ;
 
 server_options_list: