SQL 中最常用的修改表中数据的命令是 UPDATE,用于更新满足条件的行的指定列的数据。命令语法如下:UPDATE table_name SET column_name = new_value WHERE condition;。例如:UPDATE customers SET address = '123 Main Street' WHERE name = 'John' AND age > 30; 会将表 "customers" 中 "name" 列为 "John" 且 "age"
SQL 中修改表中数据的命令
SQL 中最常用的修改表中数据的命令是:
UPDATE
语法:
UPDATE table_name SET column_name = new_value WHERE condition;
作用:
- UPDATE 命令用于更新指定表中满足条件的行的指定列中的数据。
参数:
- table_name:要更新的表名。
- column_name:要更新的列名。
- new_value:要更新为的新值。
- condition:可选,指定要更新的行。如果不指定条件,则更新表中的所有行。
示例:
以下命令将表 "customers" 中 "name" 列为 "John" 且 "age" 列大于 30 的所有行的 "address" 列更新为 "123 Main Street":
UPDATE customers SET address = '123 Main Street' WHERE name = 'John' AND age > 30;
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