前面说到的 sqlite_exec() 中的第三个参数, SQLite 将为 sql 参数内执行的每个 SELECT 语句中处理的每个记录调用这个回调函数。
本节添加了两个函数,selectFromTable和updateTable.
实例程序如下:
#include
#include
#include "sqlite/sqlite3.h"
#define DB_NANE "sqlite/test.db"
sqlite3 *db = NULL;
char* sql = NULL;
char *zErrMsg = NULL;
const char* data = "Callback function called";
int ret = 0;
typedef enum{
false,
true
} bool;
static int callback(void *NotUsed, int argc, char **argv, char **azColName)
{
int i = 0;
for(i=0; i < argc; i++){
printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("\n");
return 0;
}
bool connectDB()
{
ret = sqlite3_open(DB_NANE, &db);
if( ret != SQLITE_OK){
fprintf(stderr, "Error open database: %s\n", sqlite3_errmsg(db));
sqlite3_free(zErrMsg);
return false;
}
fprintf(stdout, "Successfully opened database\n");
return true;
}
bool createTable()
{
sql = "CREATE TABLE COMPANY(" "ID INT PRIMARY KEY NOT NULL," "NAME TEXT NOT NULL," "AGE INT NOT NULL," "ADDRESS CHAR(50)," "SALARY REAL );";
ret = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
if( ret != SQLITE_OK ){
fprintf(stderr, "Error SQL: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
return false;
}
fprintf(stdout, "Successfully table created\n");
return true;
}
bool insertRecords()
{
sql = "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " "VALUES (1, 'Paul', 32, 'California', 20000.00 ); " "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY) " "VALUES (2, 'Allen', 25, 'Texas', 15000.00 ); " "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)" "VALUES (3, 'Teddy', 23, 'Norway', 20000.00 );" "INSERT INTO COMPANY (ID,NAME,AGE,ADDRESS,SALARY)" "VALUES (4, 'Mark', 25, 'Rich-Mond ', 65000.00 );";
ret = sqlite3_exec(db, sql, callback, 0, &zErrMsg);
if( ret != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
return false;
}
fprintf(stdout, "successfully records created\n");
return true;
}bool selectFromTable()
{
sql = "SELECT * from COMPANY";
ret = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
if( ret != SQLITE_OK ){
fprintf(stderr, "Error SQL: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
return false;
}
fprintf(stdout, "successfully operation done\n");
return true;
}
bool updateTable()
{
sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1; " "SELECT * from COMPANY";
ret = sqlite3_exec(db, sql, callback, (void*)data, &zErrMsg);
if( ret != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
return false;
}
fprintf(stdout, "Successfully operation done \n");
return true;
}
bool closeDB()
{
int ret = 0;
ret = sqlite3_close(db);
if ( ret == SQLITE_BUSY ){
return false;
}
return true;
}
int main(int argc, char* argv[])
{
connectDB();
selectFromTable();
updateTable();
selectFromTable();
closeDB();
return 0;
}
原文:http://blog.csdn.net/xufeng0991/article/details/38598313