SQLite第五课 应用案例

1 打开数据库文件

sqlite3* m_db = NULL;

int ret = sqlite3_open_v2("test.db", &db, SQLITE_OPEN_READWRITE, NULL);

if (ret != SQLITE_OK)

{

return;

}

2 如果表不存在，创建表

char szCreateUserDataSql[1024] = "create table if not exists tb_user (id INTEGER ,\

type INTEGER,\

kind INTEGER)";

3 创建唯一的主键ID

char szCreateUserDataSql[1024] = "create table if not exists tb_user (id INTEGER PRIMARY KEY AUTOINCREMENT,\

type INTEGER,\

kind INTEGER)";

4 查询

char szSql[1024] = {0};

sprintf(szSql, "select distinct * from tb_test");

sqlite3_stmt* stmt = NULL;

sqlite3_prepare(m_db, szSql, -1, &stmt, 0);

while (sqlite3_step(stmt) == SQLITE_ROW)

{

const unsigned char*  szPOIName = sqlite3_column_text(stmt, 0);

char szName[128] = {0};

if (szPOIName)

{

sprintf(szName, "%s", szPOIName);

}

int kx = sqlite3_column_int(stmt, 3);

float x = sqlite3_column_double(stmt, 5);

}

sqlite3_finalize(stmt);

5 获取sql执行失败的错误信息

char* errMsg = NULL;

char* szSql = "select * from address";

nRet = sqlite3_exec(pDB, szSql, NULL, NULL ,&errMsg);

if (nRet != SQLITE_OK)

{

cout<<errMsg<<endl;

sqlite3_free(errMsg);

}

注意：释放errMsg指向的内存

6 关闭数据库

sqlite3_close(db);