# 创建新表
CREATE TABLE IF NOT EXISTS dictionary(english VARCHAR(30), chinese VARCHAR(80), times SMALLINT, in_new_words SMALLINT);
# 插入数据
INSERT INTO dictionary(english, chinese, times, in_new_words) VALUES('hello', '你好', 0, 0);
# 选择记录
SELECT * FROM dictionary WHERE english = 'hello';
# 更新数据
UPDATE dictionary SET times = 1 WHERE english = 'hello';
# 删除记录
DELETE FROM dictionary WHERE english = 'hello';
# 添加列
ALTER TABLE dictionary ADD extra VARCHAR(40);
#更新结构
ALTER TABLE dictionary ALTER COLUMN english SET NOT NULL;
# 更名列
ALTER TABLE dictionary RENAME COLUMN extra TO extra_data;
# 删除列
ALTER TABLE dictionary DROP COLUMN extra_data;
# 表格更名
ALTER TABLE dictionary RENAME TO cidian;
# 删除表格
DROP TABLE IF EXISTS cidian;