C语言封装sqlite3_API

//执行类似insert,update,create,drop这些不需要结果的sql语句。

int executeNoQuery(sqlite3 *db,const char *sql)
{
sqlite3_stmt *pstmt = NULL;

if(sqlite3_prepare_v2(db,sql,strlen(sql),&pstmt,NULL)  !=  SQLITE_OK)
{
if(pstmt != NULL)
sqlite3_finalize(pstmt);
fprintf(stderr,"%s\n",sqlite3_errmsg(db));
return -1;
}
if(sqlite3_step(pstmt)  !=  SQLITE_DONE)
{
sqlite3_finalize(pstmt);
fprintf(stderr,"%s\n",sqlite3_errmsg(db));
return -1;
}
if(pstmt != NULL)
sqlite3_finalize(pstmt);
return 0;
}

//执行select查询语句

void executeWithQuery(sqlite3 *db,char ***result,int *col,const char *sql)
{
int ret,row;
char *errMsg;

ret = sqlite3_get_table(db,sql,result,&row,col,&errMsg);
if(ret != SQLITE_OK)
{
fprintf(stderr,"%s\n",errMsg);
sqlite3_free(errMsg);
return;
}
(*result)[(row+1)*(*col)] = NULL;
return;
}

调用规则：
executeNoQuery：

只需传入数据库连接，和想要执行的sql语句
executeWithQuery：除了需要传入数据库连接，以及最后一个参数sql语句，还需要传入char **array,和int ncol的地址

下面是一个例子：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sqlite3.h>

#define PRINTERROR(str)	\
do{	\
perror(str);\
exit(EXIT_FAILURE);	\
}while(0)

const char *createSQL = "create table if not exists T_Students\
(S_id integer PRIMARY KEY NOT NULL,\
S_name varchar(128),S_age integer,\
Time TimeStamp NOT NULL DEFAULT (datetime('now','localtime')));";

const char *deleteSQL = "delete from T_Students where S_name='sagarfan';";
const char *updateSQL = "update T_Students set S_age=25 where S_name='sagarfan';";
const char *insertSQL = "insert into T_Students (S_name,S_age) values('sagarfan',23);";
const char *selectSQL = "select S_name,S_age from T_Students;";

int executeNoQuery(sqlite3 *db,const char *sql);
int executeWithQuery(sqlite3 *db,char ***result,int *col,const char *sql);

int main()
{
sqlite3 *conn = NULL;
int i,ret,ncol;char sql[1024]={0};
char **array;

ret = sqlite3_open("stu.sqlite",&conn);
if(ret != SQLITE_OK)
PRINTERROR(sqlite3_errmsg(conn));
//create table
ret = executeNoQuery(conn,createSQL);
if(ret == -1)
PRINTERROR(sqlite3_errmsg(conn));

ret = executeNoQuery(conn,insertSQL);
if(ret == -1)
PRINTERROR(sqlite3_errmsg(conn));

ret = executeWithQuery(conn,&array,&ncol,selectSQL);
if(ret == -1)
PRINTERROR(sqlite3_errmsg(conn));
i=0;
while(array[i+ncol] != NULL)
{
printf("Name=%s\n",array[i+ncol]);
printf("Age=%s\n",array[i+1+ncol]);
i+=ncol;
}
sqlite3_free_table(array);

ret = executeNoQuery(conn,updateSQL);
if(ret == -1)
PRINTERROR(sqlite3_errmsg(conn));

if(conn != NULL)
sqlite3_close(conn);

return 0;
}

int executeNoQuery(sqlite3 *db,const char *sql)
{
sqlite3_stmt *pstmt = NULL;

if(sqlite3_prepare_v2(db,sql,strlen(sql),&pstmt,NULL) != SQLITE_OK)
{
if(pstmt != NULL)
sqlite3_finalize(pstmt);
return -1;
}
if(sqlite3_step(pstmt) != SQLITE_DONE)
{
sqlite3_finalize(pstmt);
return -1;
}
sqlite3_finalize(pstmt);
return 0;
}

int executeWithQuery(sqlite3 *db,char ***result,int *col,const char *sql)
{
int ret,row;

ret = sqlite3_get_table(db,sql,result,&row,col,NULL);
if(ret != SQLITE_OK)
{
return -1;
}
(*result)[(row+1)*(*col)] = NULL;

return 0;
}

注意：

调用完executeWithQuery之后，记得释放array