向现有表添加索引的语法.
ALTER TABLE table_name ADD INDEX column_name
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一个简单的例子
CREATE TABLE employee_records (name VARCHAR(50), employeeID INT);
CREATE INDEX id_index ON employee_records(employeeID);
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在创建表时创建索引
CREATE TABLE employee_records (
name VARCHAR(50),
employeeID INT, INDEX (employeeID)
);
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