在MySQL中,插入数据的基本语法如下: INSERTINTO表名(列1,列2,列3,...)VALUES(值1,值2,值3,...); 1. 2. 对于多行插入,可以使用下面的形式: INSERTINTO表名(列1,列2,列3,...)VALUES(值1_1,值1_2,值1_3,...),(值2_1,值2_2,值2_3,...),(值3_1,值3_2,值3_3,...); 1. 2...
I'm looking for a way of inserting a range of values into multiple rows. I have two columns that I am inserting into - project (stays the same) and sceneno, which is where the values will increment from x-y. Basically I am trying to convert the very inefficient PHP code below into...
Inserting Multiple Rows (3:18) 小结 VALUES ……里一行内数据用括号内逗号隔开,而多行数据用括号间逗号隔开 案例 插入多条运货商信息 USE sql_store INSERT INTO shippers (name) VALUES ('shipper1'), ('shipper2'), ('shipper3'); 1. 2. 3. 4. 5. 6. 练习 插入多条产品信息 USE sql_store; ...
(1) | NO | | 男| | +---+---+---+---+---+---+ 3 rows in set (0.00 sec) mysql> insert into t13 (name,age,gender) values (NULL,'18','男'); ERROR 1048 (23000): Column 'name' cannot be null mysql> insert into t13 (age,gender) values ('18','男');//如果我们没...
Innodb_rows_updated:确认实际更新行数 慢查询日志分析:捕获执行超过long_query_time的语句 四、避坑指南 锁争用问题: 避免全表更新导致表锁 使用WHERE条件限制范围 字符集陷阱: -- 确保临时表与主表字符集一致 CREATE TEMPORARY TABLE temp_updates ( ... ) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_...
asnew rows are inserted. Thus, the rows orderedbythe row ID are physicallyininsertionorder. 间隙锁(Gap Locks) 区间锁, 仅仅锁住一个索引区间(开区间)。 在索引记录之间的间隙中加锁,或者是在某一条索引记录之前或者之后加锁,并不包括该索引记录本身。
rows:预估扫描行数 六、事务处理 START TRANSACTION; UPDATE accounts SET balance = balance - 100 WHERE user_id = 1; UPDATE accounts SET balance = balance + 100 WHERE user_id = 2; -- 提交或回滚 COMMIT; -- ROLLBACK; 事务特性(ACID): 原子性(Atomicity) 一致性(Consistency) 隔离性(Isolation...
2.1 insert 锁机制在分析死锁案例之前,我们先学习一下背景知识 insert 语句的加锁策略。我们先来看看官方定义: "An insert intention lock is a type of gap lock set by INSERT operations prior to row insertion. This lock signals the intent to insert in such a way that multiple transactions inserting ...
Query OK, 0 rows affected (0.26 sec) #char存5个字符,而varchar存4个字符 mysql> insert into t1 values('你瞅啥 ','你瞅啥 '); Query OK, 1 row affected (0.05 sec) mysql> SET sql_mode=''; Query OK, 0 rows affected, 1 warning (0.00 sec) #在检索时char很不要脸地将自己浪费的2个...
I am trying to insert a large number of rows into a mysql 5.5 database but it is very slow. Same code on POSTGRES and ORACLE is 100s times faster. For mysql I construct my INSERT statements as follows: INSERT INTO MY_TABLE VALUES ( 1, 1, 'text' ) , ( 2, 1, 'some text')...