An API demo of sqlite3

sqlite3-demo.c

/*
An API demo of sqlite3
author: Ady Liu
email: imxylz@gmail.com
web: http://www.blogjava.net/xylz/archive/2012/09/25/388519.html
*/
#include <stdio.h>
#include "sqlite3.h"

int print_record(void *,int,char **,char **);

int main(int argc,char *argv[]){
    const char *sql_drop_table="drop table if exists t";
    const char *sql_create_table="create table t(id int primary key,msg varchar(128))";
    char *errmsg = 0;
    int ret = 0;
    int i = 0;
    sqlite3_stmt *stmt;
    char ca[255];

    char **dbresult;
    int j,nrow,ncolumn,index;

    sqlite3 *db = 0;
    ret = sqlite3_open("./sqlite3-demo.db",&db);
    if(ret != SQLITE_OK){
        fprintf(stderr,"Cannot open db: %s\n",sqlite3_errmsg(db));
        return 1;
    }
    printf("Open database\n");

    ret = sqlite3_exec(db,sql_drop_table,NULL,NULL,&errmsg);
    if(ret != SQLITE_OK){
        fprintf(stderr,"drop table fail: %s\n",errmsg);
    }
    ret &= sqlite3_exec(db,sql_create_table,NULL,NULL,&errmsg);
    if(ret != SQLITE_OK){
        fprintf(stderr,"create table fail: %s\n",errmsg);
    }

    ret = sqlite3_exec(db,"insert into t(id,msg) values(1,'Ady Liu')",NULL,NULL,&errmsg);
    printf("Insert a record %s\n",ret == SQLITE_OK ? "OK":"FAIL");
    ret = sqlite3_exec(db,"insert into t(id,msg) values(2,'IMXYLZ')",NULL,NULL,&errmsg);
    printf("Insert a record %s\n",ret == SQLITE_OK ? "OK":"FAIL");
    ret = sqlite3_exec(db,"delete from t where id < 3",NULL,NULL,&errmsg);
    printf("Delete records: %s\n",ret == SQLITE_OK ? "OK":"FAIL");


    //prepare statement
    sqlite3_prepare_v2(db,"insert into t(id,msg) values(?,?)",-1,&stmt,0);
    for(i=10;i<20;i++){
        sprintf(ca,"HELLO#%i",i);
        sqlite3_bind_int(stmt,1,i);
        sqlite3_bind_text(stmt,2,ca,strlen(ca),SQLITE_STATIC);
        sqlite3_step(stmt);
        sqlite3_reset(stmt);
    }
    sqlite3_finalize(stmt);

    //select data
    ret = sqlite3_exec(db,"select * from t",print_record,NULL,&errmsg);
    if(ret != SQLITE_OK){
        fprintf(stderr,"query SQL error: %s\n",errmsg);
    }

    sqlite3_exec(db,"update t set msg='MESSAGE#10' where id=10",NULL,NULL,&errmsg);
    //select table
    ret = sqlite3_get_table(db,"select * from t",&dbresult,&nrow,&ncolumn,&errmsg);
    if(ret == SQLITE_OK){
        printf("query %i records.\n",nrow);
        index=ncolumn;
        for(i=0;i<nrow;i++){
            printf("[%2i]",i);
            for(j=0;j<ncolumn;j++){
                printf(" %s",dbresult[index]);
                index++;
            }
            printf("\n");
        }
    }else{
        fprintf(stderr,"query with get_table error: %s\n",errmsg);
    }
    sqlite3_free_table(dbresult);

    ret = sqlite3_exec(db,"delete from t",NULL,NULL,&errmsg);
    if(ret == SQLITE_OK){
        printf("delete records: %i\n",sqlite3_changes(db));
    }

    sqlite3_free(errmsg);
    sqlite3_close(db);

    printf("Close database\n");

    return 0;
}

int print_record(void *params,int n_column,char **column_value,char **column_name){
    int i;
    for(i=0;i<n_column;i++){
        printf("\t%s",column_value[i]);
    }
    printf("\n");
    return 0;
}