SELECT ... INTOsyntax enables selected columns to be stored directly into variables. The query should return a single row. If the query returns no rows, a warning with error code 1329 occurs (No data), and the variable values remain unchanged. If the query returns multiple rows, error 1172...
SELECT VERSION()查看数据库当前版本 0.2 MYSQL ERROR CODE 错误编号(合集) 0.3 SQLSTATE[HY000]:执行查询后出现常规错误 SQLSTATE[HY000]是一种SQL语句执行错误的状态码,表示在执行查询时发生了常规错误。 该错误码是由SQL标准定义的,不仅适用于特定的数据库系统,也适用于各种关系型数据库。 常规错误可能包括以下几...
If it is possible that the statement may retrieve multiple rows, you can use LIMIT 1 to limit the result set to a single row. SELECT id, data INTO @x, @y FROM test.t1 LIMIT 1;User variable names are not case-sensitive. See Section 9.4, “User-Defined Variables”. ...
There could be multiple tables/indexes in the same space, so we will mark it later in upper layer */ buf_read_page_handle_error(bpage); return (false); } } DBUG_EXECUTE_IF("buf_page_import_corrupt_failure", page_not_corrupt : bpage = bpage;); if (recv_recovery_is_on()) { /*...
SELECT*FROM(VALUESROW(2,4,8))AStINTO@x,@y,@z;SELECT*FROM(VALUESROW(2,4,8))ASt(a,b,c)INTO@x,@y,@z; User variable names are not case-sensitive. SeeSection 11.4, “User-Defined Variables”. TheSELECT ... INTO OUTFILE 'file_name'form ofSELECTwrites the selected rows to a file...
上面说到,InnoDB存储引擎在做SELECT、INSERT、DELETE、UPDATE操作的时候,不会为表加上S锁或者X锁的,但是会使用到意向锁这种表级别锁。MyISAM引擎是不支持意向锁的。 意向锁又分为意向共享锁(intention shared lock,IS):事务有意向对表中的某些行加共享锁(S锁);意向排他锁(intention exclusive lock,IX):事务有意...
SELECT order_id, quantity, unit_price FROM order_details WHERE quantity < 500 ORDER BY quantity INTO OUTFILE 'results.txt' FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '"' LINES TERMINATED BY '\n'; This MySQL SELECT example would return only the order_id, quantity, and unit_price field...
mysql> insert into test_table(id,password) values('2','test2'); Query OK, 1 row affected (0.19 sec) mysql> select * from test_table; ERROR 1044 (42000): poolName=myslave, no valid pools 1. 2. 3. 4. 5. 可以看到插入成功,读取失败 开启slavedb上的mysql,查看数据是否自动同步 slavedb...
Use RETURN instead of SET at function return point : BEGIN RETURN (SELECT A INTO FROM T WHERE ID = 22); -- say there is no such a row -- in this case return value is NULL END; 2. Use CONDITON HANDLER. Recommended and suitable for multiple variables : BEGIN DECLARE COL_A, COL_...
##将上一个测试中的数据导出,2行数据一共81Mmysql>select*intooutfile'/tmp/t1.csv'fromt1;Query OK,2rowsaffected(0.57sec)[root@localhost~]# ll -h /tmp/t1.csv-rw-r--- 1 mysql mysql 81M 6月 6 15:32 /tmp/t1.csv##MySQL Server max_allowed_packet=16Mmysql>select@@max_allowed_packet...