The basic operation of adding and deleting the database of IOS database FMDN

Fmdb (https://github.com/ccgus/fmdb) Words do not say the first to add this library, in will add in, OK ready to work on the code.

#import "DDViewController.h"

#import "FMDB.h"

@interface ddviewcontroller ()

{

fmdatabase *db;

}

@end

@implementation Ddviewcontroller

/**

* to have a location to store the database iOS document Path,document is a writable folder in iOS and to create a list of databases

*/

-(void) viewdidload

{

[superviewdidload];

db = [Fmdatabase new];

nsarray *paths =nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, YES);

nsstring *documentdirectory = [Paths objectatindex:0];

//dbpath: The database path, in Document .

nsstring *dbpath = [documentdirectory stringbyappendingpathcomponent:@ "test.db"];

// Create A DB instance here is the following: if a "test.db" file does not exist in the path , SQLite will automatically create " Test.db "

db= [fmdatabasedatabasewithpath:d Bpath];

if (! [db open]) {

NSLog(@ "Could not open db.") );

return ;

}

// set up cache for database to improve query efficiency

[dbsetshouldcachestatements:YES];

1. Create a table the name of the table to be User

[self creattable];

//2. adding data to a table

[selfinsertdata:@ " straw hat " age: +];

//3. View Results

[self ResultSet];

}

// Create a table

-(void) creattable

{

// when creating a table, it's best to judge your work before you do it.

if (! db) {

NSLog (@ " database does not exist ");

}

if (! [db open]) {

[dbopen];

}

// to determine if there is a table with this name as User if not created

if (! [db tableexists:@ "User"]) {

// Create a table named User with two fields of type string name,age of type integer

[dbexecuteupdate:@ "CREATE TABLE User (Name text,age integer)"];

[Self insertdata:@ " straw Hat " age:24];

}

}

// Insert Data

-(void) InsertData: (nsstring *) name Age: (int.) Age

{

// Insert data using type text in OC corresponding to integer type nsstring integer corresponding to int

[dbexecuteupdate:@ "INSERT into User (name,age) VALUES (?,?)" , name,[nsnumbernumberwithint: Age]];

}

// Query Results

-(void) ResultSet

{

// Returns the result of the first satisfying condition in the database

nsstring *aa=[dbstringforquery:@ "Select Name from User WHERE age =? " ,@ "+"];

NSLog(@ "AA is%@", aa);

fmresultset *rs=[dbexecuteQuery:@ "SELECT * FROM User "];

Rs=[db executequery:@ "SELECT * from User WHERE age =?", @ "23"];

while ([Rs next]) {

NSLog(@ "%@%@", [rsstringforcolumn:@ "Name"],[ RSstringforcolumn:@ "age"]);

}

[Rsclose];

}

// Modify table Contents

-(void) Modify

{

[dbexecuteupdate:@ "UPDATE User SET Name =? WHERE Name =? @" John Doe ",@ " Zhang San "];

}

-(void) didreceivememorywarning

{

[superdidreceivememorywarning];

//Dispose of any resources, can be recreated.

}

@end

IOS Database Fmdn database additions and deletions to change the basic operation