iOS database Operation flow

The latest version of SQLite is 3.0 and should be imported before using Libsqlite3.0.dylib

1. Import process

　　　　

　　　

Process of manipulating databases in 2.iOS

Open Database

Preparing the SQL database

Execute SQL database

End of statement

Close the database

3.SQLite () uses C's function interface

　　　　

4. Create a Database

　　

-(void) createsql{nsfilemanager *manager = [Nsfilemanager Defaultmanager];        if ([manager Fileexistsatpath:kdatabasefilepath]) {NSLog (@ "database does not exist");    Return    } NSLog (@ "%@", Kdatabasefilepath);            [Manager Createfileatpath:kdatabasefilepath Contents:nil Attributes:nil];    Sqlite3 *sql =null;        int opendbresult = Sqlite3_open ([Kdatabasefilepath utf8string], &sql);    if (OPENDBRESULT==SQLITE_OK) {NSLog (@ "Database open successfully");                } else{NSLog (@ "open unsuccessful");        [Manager Removeitematpath:kdatabasefilepath Error:nil];    Return } nsstring *sqlstring = @ "CREATE TABLE user (id integer PRIMARY KEY autoincrement, username text not NULL uniqu                        E, password text not NULL); ";    char *errmsg = NULL;        int exeresult = sqlite3_exec (sql, [sqlString utf8string], NULL, NULL, &ERRMSG);            if (Exeresult = = SQLITE_OK) {NSLog (@ "table was created successfully");      } else{NSLog (@ "failed");  Sqlite3_close (SQL);        [Manager Removeitematpath:kdatabasefilepath Error:nil];    Return                } sqlite3_close (SQL); }

5. Database Insert Database

　　　

-(void) createsql{nsfilemanager *manager = [Nsfilemanager Defaultmanager];        if ([manager Fileexistsatpath:kdatabasefilepath]) {NSLog (@ "database does not exist");    Return    } NSLog (@ "%@", Kdatabasefilepath);            [Manager Createfileatpath:kdatabasefilepath Contents:nil Attributes:nil];    Sqlite3 *sql =null;        int opendbresult = Sqlite3_open ([Kdatabasefilepath utf8string], &sql);    if (OPENDBRESULT==SQLITE_OK) {NSLog (@ "Database open successfully");                } else{NSLog (@ "open unsuccessful");        [Manager Removeitematpath:kdatabasefilepath Error:nil];    Return } nsstring *sqlstring = @ "CREATE TABLE user (id integer PRIMARY KEY autoincrement, username text not NULL uniqu                        E, password text not NULL); ";    char *errmsg = NULL;        int exeresult = sqlite3_exec (sql, [sqlString utf8string], NULL, NULL, &ERRMSG);            if (Exeresult = = SQLITE_OK) {NSLog (@ "table was created successfully");      } else{NSLog (@ "failed");  Sqlite3_close (SQL);        [Manager Removeitematpath:kdatabasefilepath Error:nil];    Return                } sqlite3_close (SQL); }

　　

iOS database Operation flow