information_schema.columns WHERE table_name = 'your_table_name' AND column_name = 'your_column_name' ) INTO col_exists; -- 如果列不存在,则添加新列 IF NOT col_exists THEN EXECUTE format('ALTER TABLE your_table_name ADD COLUMN your_column_name %s', 'data_type'); END IF; END $$; ...
IFNOTEXISTS(SELECT*FROMINFORMATION_SCHEMA.COLUMNS WHERETABLE_NAME='LandlordInfo'ANDCOLUMN_NAME='IsSigned') BEGIN ALTERTABLELandlordInfoADDIsSignedbitnull END
方法二 mysql 批量为表添加多个字段 alter table 表名 add (字段1 类型(长度),字段2 类型(长度),字段3 类型(长度)); 3.删除一个字段 4.修改一个字段 5.批量修改字段名称 例子: 6,添加注释 7,调整字段顺序: alter table 表名 change 字段名 新字段名 字段类型 默认值 after 字段名(跳到哪个字段之后) ...
If you look at the RowCount parameter, you can clearly see the difference. Though column is added in the first case, none of the rows are affected while in the second case all the rows are updated. That is the reason, why it has taken more duration and CPU to add column with Default...
CREATE TABLE IF NOT EXISTS table_name (...); ALTER TABLE table_name ADD COLUMN column_name datatype; 1. 2. 3. 4. 5. 6. 7. 8. 9. 3. 主键/唯一键冲突 典型错误: 复制下载 ERROR 1062 (23000): Duplicate entry 'value' for key 'PRIMARY' ...
CREATE DATABASE [IF NOT EXISTS] db_name [LOCATION 'path'] [COMMENT database_comment]; 1. IF NOT EXISTS,如存在同名数据库不执行任何操作,否则执行创建数据库操作 [LOCATION],自定义数据库存储位置,如不填写,默认数据库在HDFS的路径为:/user/hive/warehouse ...
select * from table_name where not_exist_col in (select id from table_name limit 0); 报错信息: FAILED: ODPS-0130071:[2,7] Semantic analysis exception - column not_exist_col cannot be resolved ctas.if.not.exists 目标表语法错误问题。 如果目标表已经存在,旧版MaxCompute不会做任何语法检查,MaxC...
--Replace with your ACTUAL exampleALTERTABLEIF EXISTSusercenter.dict_surgeriesADD COLUMN IF NOT EXISTS operation_grade_id int8NULL; Software Information: JSqlParser version 4.7 Database (PostgreSQL ) Tips: Please write in English and avoid Screenshots (as we can't copy and paste content from it...
IF NOT EXISTS --now finally we can make it not null (SELECT * FROM sys.columns WHERE name LIKE 'word' AND is_nullable = 0) ALTER TABLE CountingWords ALTER COLUMN Word NVARCHAR(30) NOT NULL; END; GO IF EXISTS --do we need to add in the welsh words we didn't know ...
create table IF NOT EXISTS database_name.table_name ( column1 data_type, column2 data_type, column3 data_type, ……… columnN data_type ); 例子: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 CREATE TABLE IF NOT EXISTS my_db.student(name STRING, age INT, contact INT ); 默认建...