SQLite函数与语句

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_ROW

5.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

SQLite语句

/*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 = &＃8216;MM&＃8217; WHERE age = 10;

UPDATE t_student SET name = &＃8216;WW&＃8217; WHERE age is 7;

UPDATE t_student SET name = &＃8216;XXOO&＃8217; WHERE age <20;

UPDATE t_student SET name = &＃8216;NNMM&＃8217; WHERE age <50 and score > 10;

/*删除数据*/

DELETE FROM t_student;

/*更新数据*/

UPDATE t_student SET name = &＃8216;LNJ&＃8217;;

/*插入数据*/

INSERT INTO t_student(age, score, name) VALUES (&＃8217;28&＃8217;, 100, &＃8216;jonathan&＃8217;);

INSERT INTO t_student(name, age) VALUES (&＃8216;lee&＃8217;, &＃8217;28&＃8217;);

INSERT INTO t_student(score) VALUES (100);

/*插入数据*/

INSERT INTO t_student(name, age, score) VALUES (&＃8216;lee&＃8217;, &＃8217;28&＃8217;, 100);

/*添加主键*/

CREATE TABLE IF NOT EXISTS t_student (id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT, age INTEGER, score REAL);

CREATE TABLE IF NOT EXISTS t_student (id INTEGER PRIMARY KEY, name TEXT, age INTEGER, score REAL);

CREATE TABLE IF NOT EXISTS t_student (id INTEGER, name TEXT, age INTEGER, score REAL, PRIMARY KEY(id));

/*删除表*/

DROP TABLE t_student;

DROP TABLE IF EXISTS t_student;

/*创建表*/

CREATE TABLE t_student(id INTEGER , name TEXT, age , score REAL);

CREATE TABLE IF NOT EXISTS t_student(id INTEGER , name TEXT, age , score REAL);