ALTER TABLE - DROP COLUMN To delete a column in a table, use the following syntax (notice that some database systems don't allow deleting a column): ALTERTABLEtable_name DROPCOLUMNcolumn_name; The following SQL deletes the "Email" column from the "Customers" table: ...
To use an object type in a column definition when modifying a table, either that object must belong to the same schema as the table being altered, or you must have either theEXECUTEANYTYPEsystem privilege or theEXECUTEschema object privilege for the object type. See Also: CREATE INDEXfor inf...
sqlite中ALTER TABLE语句不支持DROP COLUMN,只有RENAME 和ADD 解决办法: 1.创建一个临时表,把除了要删的字段以外的字段加上 create table _temp as select _id,name,age,balancefromperson; select*from_temp; 2.删除原表 drop table person; 3.把临时表命名成原表 alter table _temp rename to person; 即可...
ALTERTABLEdb_name.table_nameDROP[COLUMN] column_name 注意事项 不支持删除主键列。 示例 在customer表中删除类型为VARCHAR的province列。 ALTERTABLEadb_demo.customerDROPCOLUMNprovince; 变更列名 语法 ALTERTABLEdb_name.table_name RENAMECOLUMNcolumn_nametonew_column_name ...
syntaxsql Copy ALTER TABLE { database_name.schema_name.table_name | schema_name.table_name | table_name } { ALTER COLUMN column_name { [ type_schema_name. ] type_name [ ( { precision [ , scale ] | max | xml_schema_collection } ) ] [ COLLATE collation_name ] [ NULL | NOT ...
The statement takes any of the following syntaxes based on what attributes we wish to modify in a table. ALTERTABLEname RENAMETOnew_nameALTERTABLEnameADDCOLUMNS (col_spec[, col_spec ...])ALTERTABLEnameDROP[COLUMN]column_name --- 译注:这个drop命令,我在工作中,并没有生效,而是利用表级别的REPL...
Drop column(s) in a table Syntax #1 To drop a column in an existing table, the ALTER TABLE syntax is: ALTER TABLE table_name DROP COLUMN column_name; For Example: ALTER TABLE supplier DROP COLUMN supplier_name; This will drop the column calledsupplier_namefrom the table calledsupplier. ...
SELECT@sql='ALTER TABLE #temp3 ADD '+QUOTENAME(@nome)+' INT'EXEC(@sql); Otherwise, SQL Server is trying to add a column calledVerywith a datatype ofBad, and it doesn't even know how to interpretintafter that. if object_id(N'#tempg')isnotnulldroptable#tempgselect1asiinto#tempgse...
ALTER TABLE table_name { ADD COLUMN clause | ALTER COLUMN clause | DROP COLUMN clause | RENAME COLUMN clause } ADD COLUMN 子句JDBC 数据源不支持此子句。向表添加一列或多列,或将字段添加到 Delta Lake 表中的现有列。备注 向现有 Delta 表添加列时,无法定义 DEFAULT 值。 对于现有行,...
public boolean supportsAlterTableWithDropColumn() 傳回值 如果支援,則為true。 否則為false。 例外狀況 SQLServerException 備註 這個supportsAlterTableWithDropColumn 方法是由 java.sql.DatabaseMetaData 介面中的 supportsAlterTableWithDropColumn 方法指定。