mysql> create table A (id int, name varchar(20)); Query OK, 0 rows affected (0.02 sec) mysql> insert into A values (1, "张三疯"), (2, "夏洛特"), (3, "熊大"), (4, "刻晴"), (5, "急先锋"); Query OK, 5 rows affected (0.01 sec) Records: 5 Duplicates: 0 Warnings: 0...
MySQL> alter table t1 add i int; Query OK, 0 rows affected (0.41 sec) Records: 0 Duplicates: 0 Warnings: 0 #然后再次执行sp,就会发现这次执行了这句SQL的prepare再进行execute。 MySQL> call p1; Query OK, 0 rows affected (34.24 sec)
在MySQL的sp操作中涉及表操作的sql语句一定会执行check_and_update_table_version这个函数,每次会根据这个函数的结果来确定要不要重新parse该sql语句,如果没有版本改变就直接进行execute操作,如果有改变就重新parse,先prepare再execute,这样可以保证每次执行sp的SQL语句的时候表结构一定是最新的。 一、MySQL的sp运行sql语句...
After pt-table-checksum finishes checksumming all of the chunks in a table, it pauses and waits for all detected replicas to finish executing the checksum queries. Once that is finished, it checks all of the replicas to see if they have the same data as the master, and then prints a li...
mysql>alter table sc drop foreign key sc_ibfk_1; Query OK,0rows affected (0.03sec) Records:0Duplicates:0Warnings:0mysql>ALTER TABLE sc ADD CONSTRAINT sc_ibfk_1 FOREIGN KEY(sno) REFERENCES student(sno); Query OK,1row affected (0.15sec) ...
MySQL> call p1; #这里第二次操作,直接执行update这句SQL的execute。 Query OK, 0 rows affected (13.78 sec) #接着我们执行表结构的更新。 MySQL> alter table t1 add i int; Query OK, 0 rows affected (0.41 sec) Records: 0 Duplicates: 0 Warnings: 0 ...
mysql数据库sql 赞收藏 分享 阅读1.5k发布于2021-11-19 GreatSQL社区 8声望6粉丝 GreatSQL是由万里数据库维护的MySQL分支,专注于提升MGR可靠性及性能,支持InnoDB并行查询特性,是适用于金融级应用的MySQL分支版本。 « 上一篇 下一篇 » 在Ubuntu下编译安装GreatSQL ...
What to doCheck for duplicate field names and change the duplicates to distinct field names. Top of Page ACCWeb103079 Error textType mismatch in expression. What it meansThe types on either side of the join are incompatible or the field types compared are incompatible types. For example, ...
Check constraints or partition function of source table ALTER TABLE with variable TableName ALTER vs UPDATE when creating a new column with default value. Alternate queries for MERGE Alternative for OR in WHERE clause Alternative for PIVOT Alternative of CURSOR in SQL to improve performance ?
mysql> alter table t1 modify c2 varchar(4) collate utf8mb4_0900_ai_ci; #修改为NO PAD的Collation Query OK, 0 rows affected (0.15 sec) Records: 0 Duplicates: 0 Warnings: 0 mysql> insert into t1 select 1,' '; #c2字段插入两个空格 Query OK, 1 row affected (0.12 sec) Records: 1 ...