CREATE PROCEDURE MaxValue (IN column_name VARCHAR(25), OUT max_value INT) BEGIN SELECT MAX(column_name) INTO max_value FROM table_name; END; 在这个存储过程中,我们需要传入列名作为输入参数,然后使用SELECT语句和MAX函数计算最大值,并将结果存储到输出变量中。请注意,你需要将表名和列名替换为你所使用...
### 先查看下默认读取sql文件大小 mysql> show VARIABLES like '%max_allowed_packet%'; +---+---+ | Variable_name | Value | +---+---+ | max_allowed_packet | 67108864 | -- 指mysql服务器端和客户端在一次传送数据包的过程当中最大允许的数据包大小 64M | mysqlx_max_allowed_packet | 6710...
| INSERT_METHOD [=] { NO | FIRST | LAST }| KEY_BLOCK_SIZE [=] value| MAX_ROWS [=] value| MIN_ROWS [=] value| PACK_KEYS [=] {0 | 1 | DEFAULT}| PASSWORD [=] ‘string’| ROW_FORMAT [=] {DEFAULT | DYNAMIC | FIXED | COMPRESSED | REDUNDANT | COMPACT}| SECONDARY_ENGINE_ATT...
基本语法: INSERT INTO table_name [(column1, column2, ...)] VALUES (value1, value2, ...)[, (value1, value2, ...), ...]; 插入单条数据 INSERT INTO students (name, age, gender, class, score) VALUES ('张三', 20, '男', '计算机科学1班', 89.5); 插入多条数据 INSERT INTO stu...
WL#6204: InnoDB persistent max value for autoinc columns Description Requirements High Level Architecture Low Level Design SeeBUG#199on MySQL bugs. Currently InnoDB does the following when a table is opened: SELECT MAX(c) FROM t; where c is the AUTOINC column name. This step is used to initi...
“What is the highest item number?” SELECTMAX(article)ASarticleFROMshop;+---+|article|+---+|4|+---+ PREVHOMEUPNEXT
PARTITION p3 VALUES LESS THAN (MAXVALUE,MAXVALUE) ); 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 注意:多字段的分区键比较是基于数组的比较。它先用插入的数据的第一个字段值和分区的第一个值进行比较,如果插入的第一个值小于分区的第一个值那么就不需要比较第二个值就属于该分区;如果第一个值等于分区...
ERROR 1439 (42000): Display width out of range for column 'x' (max = 255) mysql> create table t1(x float(255,30)); #建表成功 Query OK, 0 rows affected (0.02 sec) mysql> create table t2(x double(255,30)); #建表成功 Query OK, 0 rows affected (0.02 sec) mysql> create table...
MySQL 数据库连接失败,报错com.mysql.jdbc.PacketTooBigException: Packet for query is too large ( 4739923 > 1948576). You can change this value on the server by setting the max_ allowed_ packet' variable 原因分析: 本地MySQL 数据库中「max_allowed_packet」值设置过小导致单个记录超过限制后写入数据...
ERROR1439(42000): Display widthoutofrangeforcolumn'weight'(max=255) # 说显示宽度超过了255createtablef2(weightfloat(255,31)); ERROR1425(42000): Too big scale31specifiedforcolumn'weight'. Maximumis30.# 告诉我们小数点后的位数最多30位createtablef3(weightfloat(255,30)); # 这样就没问题了descf3...