/*
+--------+ +-------+ +--------------+ +---------------+
| B-tree | --> | Pager | --> | os | --> | Database File |
+--------+ +-------+ +--------------+ +---------------+
 |
 |
 v
 +--------------+
 | Journal File |
 +--------------+
*/
#include <stdio.h>
#include <stdlib.h>
#include <sqlite3.h>

static int callback(void *NotUsed, int argc, char **argv, char **azColName){
 int i;
 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; 
 char *sql; 

 /* Open database */
 //< 如果文件存在就打开数据库文件
 //< 如果文件不存在就打开一个数据库,等有实际操作了在创建该数据库文件
 
 rc = sqlite3_open("test.db", &db);
 if( rc ){
 fprintf(stderr, "Can't open database: %s\n", sqlite3_errmsg(db));
 exit(0);
 }else{
 fprintf(stdout, "Opened database successfully\n");
 }

 /* Create SQL statement */
 //< 建表语句定义
 /* 创建主键 */ //"ID INT PRIMARY KEY NOT NULL," 
 sql = "CREATE TABLE COMPANY(" \
 "id INT PRIMARY KEY NOT NULL," \
 "name TEXT NOT NULL," \
 "age INT NOT NULL," \
 "address CHAR(50)," \
 "salary REAL );";

 /* Execute SQL statement */
 //< 返回程序生成的执行的任何返回
 rc = sqlite3_exec(db, sql, callback, 0, &zErrMsg);

 //< insert 
 sql = "insert into company()";
 
 if( rc != SQLITE_OK ){
 fprintf(stderr, "SQL error: %s\n", zErrMsg);
 sqlite3_free(zErrMsg);
 }else{
 fprintf(stdout, "Table created successfully\n");
 }
 sqlite3_close(db);
 return 0;
}