INSERT INTO `t1` (`id`,`batchid`,`state`) VALUES (2,1,1); drop procedure if exists p; delimiter $$ CREATE PROCEDURE `p`() begin if not exists (select * from t1 where id=1) then select 'id=1 not exists'; end if; end $$ delimiter ; 按照如下时间轴执行 ,窗口二居然被阻塞了....
以下是使用IF NOT EXISTS语法创建表的示例代码: # 创建表sql=f"CREATE TABLE IF NOT EXISTS{table_name}(id INT, name VARCHAR(255))"cursor.execute(sql)print(f"表{table_name}创建成功") 1. 2. 3. 4. 在上述代码中,我们使用了CREATE TABLE IF NOT EXISTS语句来创建表。如果表已经存在,这条语句会被...
LIKE. Replication of CREATE TABLE IF NOT EXISTS ... SELECT follows somewhat different rules; see Section 16.4.1.6, “Replication of CREATE TABLE ... SELECT Statements”, for more information. CREATE EVENT IF NOT EXISTS is always replicated, whether or not the event named in the statement ...
CREATE EVENT IF NOT EXISTSis always replicated, whether or not the event named in the statement already exists on the source. CREATE USERis written to the binary log only if successful. If the statement includesIF NOT EXISTS, it is considered successful, and is logged as long as at least ...
2.对于插入数据,IF NOT EXISTS不是直接支持的,但你可以通过编写一个条件语句来模拟这种行为: INSERTINTOtable_name (column1, column2)SELECTvalue1, value2FROMdualWHERENOTEXISTS(SELECT1FROMtable_nameWHEREcondition ); 在这个例子中,dual是一个虚拟表,SELECT语句从中选择数据,而WHERE NOT EXISTS子句检查在目标表...
对于MariaDB,从10.2.1开始,其支持DROP CONSTRAINT子句,并引入了DEFAULT约束,还支持check约束。且在MariaDB 10.0.2版本之后,操作字段时甚至支持if exists和if not exists。包括如下情况: 1 2 3 4 5 6 7 8 9 10 11 12 13ADDCOLUMN[IFNOTEXISTS]ADDINDEX [IFNOTEXISTS]ADDFOREIGNKEY [IFNOTEXISTS]ADDPARTITION...
mysql> ? create table Name: 'CREATE TABLE' Description: Syntax: CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name (create_definition,...) [table_options] [partition_options] data_type: (see https://dev.mysql.com/doc/refman/8.0/en/data-types.html) index_type: USING {BTREE | HASH}...
OceanBase 数据库 MySQL 租户 3.2.3 版本支持创建临时表。 创建表时,不支持创建基于查询的表:create table as select,会输出空字符串。 创建表的语法总览如下: CREATE[TEMPORARY]TABLE[IFNOTEXISTS]tbl_name(create_definition,...)[table_options][partition_options] ...
)[table_options]CREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name[(create_definition,…)][table_options][partition_options][IGNORE | REPLACE][AS] query_expressionCREATE [TEMPORARY] TABLE [IF NOT EXISTS] tbl_name{ LIKE old_tbl_name | (LIKE old_tbl_name) } create_definition: {col_name ...
Description:1、create table t(id1 int,id2 int,id3 int, unique key(id2,id3)); 2、insert into t values(1,1,1); insert into t7 values(20,20,20); 3、create a procedure: delimiter // create procedure p() begin if(not exists (select 1 from t where id2=6 and id3=6)) then se...