sqlite3数据库c语言常用接口应用实例

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

/***************************
typedef int (*sqlite3_callback)(
void*,    // Data provided in the 4th argument of sqlite3_exec()
int,        // The number of columns in row
char**,   // An array of strings representing fields in the row
char**    // An array of strings representing column names
);

***************************/

/* callback函数只有在对数据库进行select, 操作时才会调用 */
static int select_callback(void *data, int argc, char **argv, char **azColName){
int i;
printf("%s", (char*)data);
for(i=0; i < argc; i++){
printf("%s = %s\n", azColName[i], argv[i] ? argv[i] : "NULL");
}
printf("\n");
return 0;
}

int main(int argc, char* argv[])
{
sqlite3 *db;
char *zErrMsg = 0;
int rc;

/* 数据库创建或打开 */
rc = sqlite3_open("test.db", &db);

if( rc ){
fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
exit(0);
}else{
fprintf(stderr, "Opened database successfully\n");
}

char* sql;
sql = "create table healthinfo (" \
"sid int primary key not null," \
"name text not null," \
"ishealth char(4) not null);";

/* 创建表 */
rc = sqlite3_exec(db, sql, NULL, NULL, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table created successfully\n");
}

sql = "insert into healthinfo (sid, name, ishealth)" \
"values (201601001, 'xiaowang', 'yes');" \
"insert into healthinfo (sid, name, ishealth)" \
"values (201601002, 'xiaoli', 'yes');" \
"insert into healthinfo (sid, name, ishealth)" \
"values (201601003, 'xiaozhang', 'no');" \
"insert into healthinfo (sid, name, ishealth)" \
"values (201601004, 'xiaozhou', 'yes');" \
"insert into healthinfo (sid, name, ishealth)" \
"values (201601005, 'xiaosun', 'yes');";

/* 插入数据 */
rc = sqlite3_exec(db, sql, NULL, NULL, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table insert data successfully\n");
}

char* strname = "xiaoyang";
//char strname[256] = {'x','i','a','o','y','a','n','g'};
char sql2[256] = {'0'};
/* 不推荐使用这种方式 */
sprintf(sql2, "insert into healthinfo (sid, name, ishealth) values (201601006, '%s', 'yes');", strname);
/* 插入数据 */
rc = sqlite3_exec(db, sql2, NULL, NULL, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table insert data successfully\n");
}

/***********  存数据和取数据的第二种方法***********/

sql = "insert into healthinfo (sid, name, ishealth)" \
"values (:sid, :name, :ishealth);";   /* 注: ":sid" 为命名参数 也可以用? 号*/

sqlite3_stmt *stmt;
/* 准备一个语句对象 */
sqlite3_prepare_v2(db, sql, strlen(sql), &stmt, NULL);
/* 语句对象绑定的参数个数也就是上面sql语句values括号中的参数 */
printf("max_parameter_count = %d\n", sqlite3_bind_parameter_count(stmt));
/* 只有上面指定了:sid这个名字才可以用 */
printf("sid parameter index = %d\n", sqlite3_bind_parameter_index(stmt, ":sid"));
printf("name parameter index = %d\n", sqlite3_bind_parameter_index(stmt, ":name"));
printf("ishealth parameter index = %d\n", sqlite3_bind_parameter_index(stmt, ":ishealth"));
/* 如果是?号命名的则返回的文本为null */
printf("index = 1 's parameter's name = %s\n", sqlite3_bind_parameter_name(stmt, 1));
sqlite3_bind_int(stmt, 1, 201601007);
sqlite3_bind_text(stmt, 2, "xiaoqian", -1, NULL); /* 第四个参数设为负数则自动计算第三个参数的长度 */
sqlite3_bind_text(stmt, 3, "yes", 3, NULL);
//sqlite3_bind_blob(stmt, 1, sectionData, 4096, SQLITE_STATIC); /* 将sectonData 绑定到stmt对象 */

/* 执行sql 语句对象并判断其返回值
发现如果不是select 这样会产生结果集的操作
返回值为SQLITE_DONE 或者出错，只有执行sql语句会产生
结果集执行step函数才返回SQLITE_ROW*/
rc = sqlite3_step(stmt);
printf("step() return %s\n", rc == SQLITE_DONE ? "SQLITE_DONE" \
: rc == SQLITE_ROW ? "SQLITE_ROW" : "SQLITE_ERROR");

sqlite3_reset(stmt);  /* 如果要重新绑定其他值要reset一下 */
sqlite3_bind_int(stmt, 1, 201601008);
sqlite3_bind_text(stmt, 2, "xiaowu", -1, NULL); /* 重新绑定值 */
sqlite3_bind_text(stmt, 3, "yes", 3, NULL);
sqlite3_step(stmt);  /* 再执行 */

/* 销毁prepare 创建的语句对象 */
sqlite3_finalize(stmt);

/* 取数据 */
//sql = "select * from healthinfo;";
sql = "select * from healthinfo limit 4 offset 2;";  /* 限制返回4行且从第3行开始 */
sqlite3_prepare_v2(db, sql, strlen(sql), &stmt, NULL);
printf("total_column = %d\n", sqlite3_column_count(stmt));

/* 遍历执行sql语句后的结果集的每一行数据 */
while(sqlite3_step(stmt) == SQLITE_ROW){
/* 获得字节数，第二个参数为select结果集合的列号 */
/* 由于select 的结果集只有section这一列，因此为0 */
int len_sid = sqlite3_column_bytes(stmt, 0);
int len_name = sqlite3_column_bytes(stmt, 1);
int len_ishealth = sqlite3_column_bytes(stmt, 2);

printf("sid = %d, len = %d\n", sqlite3_column_int(stmt, 0), len_sid);
printf("name = %s, len = %d\n", sqlite3_column_text(stmt, 1), len_name);
printf("ishealth = %s, len = %d\n", sqlite3_column_text(stmt, 2), len_ishealth);
//unsigned char* srcdata = sqlite3_column_blob(stmt, 0);  /* 取得数据库中的blob数据 */
}
printf("\n");
sqlite3_finalize(stmt);
/******************* end ****************************/

const char* data = "select call back function call!\n";
/* select 使用*/
sql = "select * from healthinfo where ishealth == 'yes';";
rc = sqlite3_exec(db, sql, select_callback, data, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table select successfully\n");
}

data = "update call back function call!\n";
/* update 使用*/
sql = "update healthinfo set ishealth = 'no' where name='xiaoli';" \
"select * from healthinfo where ishealth == 'yes';";
rc = sqlite3_exec(db, sql, select_callback, data, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table update successfully\n");
}

/* 删除表 */
sql = "drop table healthinfo;";
rc = sqlite3_exec(db, sql, NULL, NULL, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table droped successfully\n");
}

char sql5[256];
char* tname = "abc";
sprintf(sql5, "create table if not exists %s ("\
"id int not null," \
"name text not null);", tname);

printf("%s\n", sql5);

/* 创建表 */
rc = sqlite3_exec(db, sql5, NULL, NULL, &zErrMsg);
if( rc != SQLITE_OK ){
fprintf(stderr, "SQL error: %s\n", zErrMsg);
sqlite3_free(zErrMsg);
}else{
fprintf(stdout, "Table created successfully\n");
}

sqlite3_close(db);
}