# SQLite数据库增删改查 #
https://blog.youkuaiyun.com/liu540885284/article/details/47430807
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# Cursor #
https://blog.youkuaiyun.com/guomeijuan916/article/details/7960130
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# sql语句不要少了单引号 #
下面正确:
Cursor cursor = db.rawQuery("select count(*) from user where num='"+U_num+"' and pwd='"+U_pwd+"'",null);
下面错误:(会报错no such column)
Cursor cursor = db.rawQuery("select count(*) from user where num="+U_num+" and pwd="+U_pwd+"",null);
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# sql的自动增加列autoincrement #
初始值的设置:
https://zhidao.baidu.com/question/584972933.html