ALTER TABLE - ALTER/MODIFY DATATYPE To change the data type of a column in a table, use the following syntax: SQL Server / MS Access: ALTERTABLEtable_name ALTERCOLUMNcolumn_name datatype; My SQL / Oracle (prior version 10G): ALTERTABLEtable_name ...
alter tabel table_namedrop columncolumn_name; 要改变表中列的数据类型,不同的系统命令不同: To change the data type of a column in a table, use the following syntax: SQL Server / MS Access: ALTER TABLE table_name ALTER COLUMN column_name datatype My SQL / Oracle: ALTER TABLE table_nameM...
alter tabel table_namedrop columncolumn_name; 要改变表中列的数据类型,不同的系统命令不同: To change the data type of a column in a table, use the following syntax: SQL Server / MS Access: ALTER TABLE table_name ALTER COLUMN column_name datatype My SQL / Oracle: ALTER TABLE table_nameM...
http://www.dba-oracle.com/t_alter_table_modify_column_syntax_example.htm For complete tips on Oracle alter table syntax, see the book "Easy Oracle Jumpstart". Oracle provides "alter table" syntax to modify data columns in-place in this form: alter table table_name modify column_name datat...
ALTER TABLE customer MODIFY ( cust_name varchar2(100) not null, cust_hair_color varchar2(20) ) ; 1. 2. 3. 4. 5. We can also use Oracle "alter table" syntax in dynamic PL/SQL to modify data columns BEGIN SQL_STRING := 'ALTER TABLE '||:TABLE_NAME||' MODIFY '||:COLUMN_NAME...
Syntax ALTER TABLEtable-Name{ ADD COLUMNcolumn-definition| ADDCONSTRAINT clause| DROP [ COLUMN ] column-name [ CASCADE | RESTRICT ] DROP { PRIMARY KEY | FOREIGN KEY constraint-name | UNIQUE constraint-name | CHECK constraint-name | CONSTRAINT constraint-name } ...
The syntax for many of the permissible alterations is similar to clauses of theCREATE TABLEstatement.column_definitionclauses use the same syntax forADDandCHANGEas forCREATE TABLE. For more information, seeSection 13.1.18, “CREATE TABLE Statement”. ...
Oracle Database has two types of temporary table: global (GTT) and private (PTT).Global Temporary Tables (GTT)The syntax to create a global temporary table is:Copy code snippet Copied to Clipboard Error: Could not Copy Copied to Clipboard Error: Could not Copy create global temporary ta...
Here, the SQL command adds a column namedphoneto theCustomerstable. ALTER TABLE Syntax The syntax of the SQLALTER TABLEstatement is: ALTERTABLEtable_name clause supporting_codes; Here, table_nameis the name of the table to be modified
ALTER TABLE是一种用于修改数据库表结构的SQL语句。它允许开发人员向现有表中添加、修改或删除列,以及修改表的约束、索引和其他属性。 错误代码: 1064是MySQL数据库中的一个常见错误代码,表示SQL语法错误。当使用ALTER TABLE语句时,错误代码: 1064通常表示在语句中存在语法错误或不支持的操作。 要解决错误代码: 1064...