简介：

　　在使用到sqlite3的时候，常常需要写一些SQL语句，现将常用到的部分语句稍微总结以下，由于个人习惯，关键字用大写。 

附：

/*简单约束*/CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER);CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, age INTEGER NOT NULL);CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT UNIQUE, age INTEGER);CREATE TABLE IF NOT EXISTS t_student(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER DEFAULT 1);/*分页*/SELECT * FROM t_student ORDER BY id ASC LIMIT 30, 10;/*排序*/SELECT * FROM t_student WHERE score > 50 ORDER BY age DESC;SELECT * FROM t_student WHERE score < 50 ORDER BY age ASC , score DESC;/*计量*/SELECT COUNT(*) FROM t_student WHERE age > 50;/*别名*/SELECT name as myName, age as myAge, score as myScore FROM t_student;SELECT name myName, age myAge, score myScore FROM t_student;SELECT s.name myName, s.age myAge, s.score myScore FROM t_student s WHERE s.age > 50;/*查询*/SELECT name, age, score FROM t_student;SELECT * FROM t_student;/*修改指定数据*/UPDATE t_student SET name = 'MM' WHERE age = 10;UPDATE t_student SET name = 'WW' WHERE age is 7;UPDATE t_student SET name = 'XXOO' WHERE age < 20;UPDATE t_student SET name = 'NNMM' WHERE age < 50 and score > 10;/*删除数据*/DELETE FROM t_student;/*更新数据*/UPDATE t_student SET name = 'LNJ';/*插入数据*/ INSERT INTO t_student(age, score, name) VALUES ('28', 100, 'jonathan'); INSERT INTO t_student(name, age) VALUES ('lee', '28'); INSERT INTO t_student(score) VALUES (100);/*插入数据*/INSERT INTO t_student(name, age, score) VALUES ('lee', '28', 100);/*添加主键*/CREATE TABLE IF NOT EXISTS t_student (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER, score REAL);/*添加主键*/CREATE TABLE IF NOT EXISTS t_student (id INTEGER, name TEXT, age INTEGER, score REAL, PRIMARY KEY(id));/*删除表*/DROP TABLE IF EXISTS t_student;/*创建表*/CREATE TABLE IF NOT EXISTS t_student(id INTEGER , name TEXT, age , score REAL);

 

函数介绍：

1.打开数据库int sqlite3_open(    const char *filename,   // 数据库的文件路径    sqlite3 **ppDb          // 数据库实例);2.执行任何SQL语句int sqlite3_exec(    sqlite3*,                                  // 一个打开的数据库实例    const char *sql,                           // 需要执行的SQL语句    int (*callback)(void*,int,char**,char**),  // SQL语句执行完毕后的回调    void *,                                    // 回调函数的第1个参数    char **errmsg                              // 错误信息);3.检查SQL语句的合法性（查询前的准备）int sqlite3_prepare_v2(    sqlite3 *db,            // 数据库实例    const char *zSql,       // 需要检查的SQL语句    int nByte,              // SQL语句的最大字节长度    sqlite3_stmt **ppStmt,  // sqlite3_stmt实例，用来获得数据库数据    const char **pzTail);4.查询一行数据int sqlite3_step(sqlite3_stmt*); // 如果查询到一行数据，就会返回SQLITE_ROW5.利用stmt获得某一字段的值（字段的下标从0开始）double sqlite3_column_double(sqlite3_stmt*, int iCol);  // 浮点数据int sqlite3_column_int(sqlite3_stmt*, int iCol); // 整型数据sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol); // 长整型数据const void *sqlite3_column_blob(sqlite3_stmt*, int iCol); // 二进制文本数据const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);  // 字符串数据