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@ -248,3 +248,45 @@ CREATE table first_table( |
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second_column VARCHAR(100) |
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second_column VARCHAR(100) |
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); |
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); |
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-- 插入数据 |
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-- 不写列明 默认按照建表的顺序 (每列必须明确写出值,可以用NULL替代) |
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INSERT INTO first_table VALUE (1, '哈哈'); |
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-- 指定列名 |
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INSERT INTO first_table(first_column, second_column) VALUE (2, '嘿嘿'); |
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-- 可以调换列顺序 |
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INSERT INTO first_table(second_column, first_column) VALUE ('嘿嘿嘿', 3); |
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-- 批量插入数据 VALUE => VALUES (VALUES也可以只插入一条数据) |
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INSERT INTO |
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first_table(second_column, first_column) |
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VALUE |
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('嘿哈', 5), |
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('嗯哼', 6), |
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('唉嘿', 7), |
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('嘻嘻', 8), |
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('呜呜呜', 9); |
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-- 插入其他表的数据 |
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INSERT INTO first_table SELECT * FROM first_table LIMIT 4; |
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INSERT INTO first_table(first_column, second_column) SELECT first_column, second_column FROM first_table WHERE first_column = 3; |
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-- 删除记录 |
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DELETE FROM first_table; |
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-- 创建存储函数 |
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-- 设置分隔符 |
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SET global log_bin_trust_function_creators = TRUE; |
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DELIMITER $ |
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CREATE FUNCTION get_score_avg(subject_name VARCHAR(10)) |
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RETURNS DOUBLE |
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BEGIN |
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RETURN (SELECT AVG(student_score.score) FROM student_score WHERE subject = subject_name); |
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END $ |
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DELIMITER ; |
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SHOW FUNCTION STATUS ; |
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