sqlite学习笔记11：C语言中使用sqlite之删除记录

#include <stdio.h>
#include <stdlib.h>
#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;

/*
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
);
*/
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()
{
/* Create SQL statement */
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 */
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()
{
/* Create SQL statement */
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 );";

/* Execute SQL statement */
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()
{
/* Create SQL statement */
sql = "SELECT * from COMPANY";

/* Execute SQL statement */
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()
{
/* Create merged SQL statement */
sql = "UPDATE COMPANY set SALARY = 25000.00 where ID=1; " \
"SELECT * from COMPANY";

/* Execute SQL statement */
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 deleteTable()/*新加*/
{
/* Create merged SQL statement */
sql = "DELETE from COMPANY where ID=2; " \
"SELECT * from COMPANY";

/* Execute SQL statement */
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 closeDB()
{
int ret = 0;
ret = sqlite3_close(db);
if ( ret == SQLITE_BUSY ){
return false;
}

return true;
}

int main(int argc, char* argv[])
{
connectDB();
/*createTable();*/
/*insertRecords();*/
selectFromTable();
/*updateTable();*/
deleteTable();
selectFromTable();
closeDB();

return 0;
}