SQLite Fifth Lesson Application case

1 Open the database file

sqlite3* m_db = NULL;

int ret = SQLITE3_OPEN_V2 ("Test.db", &db, Sqlite_open_readwrite, NULL);

if (ret! = SQLITE_OK)

{

Return

}

2 If the table does not exist, create a table

Char szcreateuserdatasql[1024] = "CREATE table if not exists Tb_user (id INTEGER, \

Type integer,\

Kind INTEGER) ";

3 Creating a unique primary key ID

Char szcreateuserdatasql[1024] = "CREATE table if not exists Tb_user (ID INTEGER PRIMARY KEY autoincrement,\

Type integer,\

Kind INTEGER) ";

4 queries

Char szsql[1024] = {0};

sprintf (szSQL, "SELECT DISTINCT * from Tb_test");

sqlite3_stmt* stmt = NULL;

Sqlite3_prepare (m_db, szSQL, 1, &stmt, 0);

while (Sqlite3_step (stmt) = = Sqlite_row)

{

Const unsigned char* szpoiname = sqlite3_column_text (stmt, 0);

Char szname[128] = {0};

if (szpoiname)

{

sprintf (SzName, "%s", szpoiname);

}

int kx = Sqlite3_column_int (stmt, 3);

float x = sqlite3_column_double (stmt, 5);

}

Sqlite3_finalize (stmt);

5 get error message for SQL execution failure

char* errmsg = NULL;

char* szSQL = "SELECT * From address";

Nret = Sqlite3_exec (PDB, szsql, NULL, NULL, &ERRMSG);

if (nret! = SQLITE_OK)

{

cout<<errmsg<<endl;

Sqlite3_free (errmsg);

}

Note: Release the memory that ErrMsg points to

6 Closing the database

Sqlite3_close (DB);

SQLite Fifth Lesson Application case