realm database ios

Basic iOS _ database 3_sqlite3 operations, ios3_sqlite3Finally:Sqlite3 function Summary 1. open the database int sqlite3_open (const char * filename, // The database file path sqlite3 ** ppDb // database instance); 2. execute any SQL statement int sqlite3_exec (sqlite3 *, //

The iOS system comes with Core Data persistence, and Core Data can use a graphical interface to create objects, but Core Data not relational databases, and is Core Data better at managing data persisted on devices created by user-created objects. However, in order to process large amounts of data, it is preferable to choose SQL relational databases to store the data.Core DataSQLite is also used to store data in the background, but developers cannot ac

CoreData Database Introduction CoreData IntroductionCoreDatais a powerful data persistence technology located on the SQLite database, which avoids the complexity of SQL and allows us to interact with the database in a more natural way. CoreData provides data--oc object mapping relationships for data and object management so that you can manipulate them without an

SQLite is an embedded and lightweight SQL database. SQLite is implemented by C. It is widely used in small Web applications including browsers (most browsers that support HTML5, IE), iOS, Android, and some portable requirements.Database is nothing more than increase, delete, change, check four kinds. In addition to the query thought, the other three methods are more similar// before using the

When I create an ios interface, the other side sends multiple json strings. how can I match the json data with the database data? When I create an ios interface, the other side sends multiple json strings. how can I match the json data with the database data? My idea is to first judge the number of json strings based

(@ "Successfully open database");1. Create a table[Self executesqlite:db withsql:@ ' CREATE table if not exists t_newtable (ID integer primary key autoincrement, name text, a GE integer, Math real) "];2. Inserting data[Self executesqlite:db withsql:@ "insert to T_newtable (name, age, math) VALUES (' Tom ', 10, 100) '];3. Query data[Self quarydata:db];} else {NSLog (@ "Failed to open database, failure code:

How data is stored in iOS Plist (Nsarray\nsdictionary) Preference (Preferences \nsuserdefaults) Nscoding (Nskeyedarchiver\nskeyedunarchiver) SQlite3 Core Date Plist, Preference, nscoding storage methodsSee how iOS Development files are storedHow the database is storedCore Date: Core data is a framework that appears after IOS5, which

SQLite locksEntireDatabaseDuring a write operation (I. e. when a write is happening on any table, no other write, to any table anywhere can happen at the same time ). some databases provide concurrent writes via table-level locks, or sometimes row-level locks. to contrast this to SQLite'sImplementation, a table-Level Lock basically means that when you're writing data to a given table, no other thread can write to any record in that table, at the same time (however, writes to other tables can occ

There are four types of data persistence in iOS: Attribute lists, object archiving, SQLite3, and core Data,sqlite3 database operations are a must-have or missing technology. SQLite3 Introduction SQLite3 database is the mobile side (IOS, Android, embedded) identified on the relational

Php reads data from the database and sends it to ios through json. I read the data from the database in php, put the read data into a json string, and then send it to ios, however, I found that all the read data has changed to 1, and then I checked on the php end whether the value of one of the queries is a string that

Php reads data from the database and sends it to ios through json. I read the data from the database in php, put the read data into a json string, and then send it to ios, however, I found that all the read data has changed to 1, and then I checked on the php end whether the value of one of the queries is a string that

OverviewThis chapter is a brief illustration of the use of SQLite to persist data in iOS development, using a method that is basically consistent with the use of SQLite in C + +.results show(actually nothing to see)Process Overview1. Because the use of the previous project, so the main need to drag two more buttons, almost.2. Because you want to use SQLite, you need to refer to the SQLite Library (SQLite framework), in the project settings, as shown i

iOS Development-ui Learning-sqlite Database operationsSQLite is a lightweight database, it occupies a very low resource, in the embedded device, may only need hundreds of K of memory is enough, and it processing speed than the MySQL, PostgreSQL the two famous database is faster, Used in

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.If the iOS App is using CoreData and has database updates on the previous version (new tables, fields, and so on), the migration of the CoreData database will be done when the installer is overwritten, as follows:1. Select your Mydata.xcdatamodeld file, sele

*errmsg = NULL; int exeresult = sqlite3_exec (sql, [sqlString utf8string], NULL, NULL, AMP;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{nsf

IOS development-encapsulation database sqlite3: Why FMDB and sqlite3fmdb Why is FMDB a third-party Lightweight Framework used? FMDB is a third-party framework for Data storage. Compared with SQLite and Core Data, FMDB has many advantages. FMDB Is Object-Oriented. It encapsulates the C language API of SQLite in OC mode, which is more convenient to use and does not require much knowledge about

Many students have the idea of directly connected to these databases, if I say the following two questions you still want to connect directly, then I can'tA database is the most important part of a server, the most vulnerable part, and the most sensitive part.If the direct connection will cause the following problems1. Security issues, your connection database account password exposed to the client, so it i

In iOS, FMDB third-party SQLite database UI_20 1. What is FMDB? FMDB is an SQLite database on iOS platform, but it encapsulates SQLite statements in C language in the OC mode and is more object-oriented. 2. advantages of FMDB: 1. it is more object-oriented. 2. compared with Apple's Core Data management tools, the tool

content ' where field = ' content before change 'The set is followed by the new data,where it is followed by the previous dataEnquiry:01.select *from table name query all fields (* indicates all). 02.select field 1. Field 2....from table name;such as:select *from user; Conditional Statements:where field = content;Where field is content;// equivalent =where field ! = content. The Where field is the not content;where fields > content;where field > content and fields > content; where field > conte

data into the model and store it in an array- - Don't forget to release the statement object at the end //Find a student+ (Student *) Findstudentbyid: (int) id{//Open DatabaseSqlite3 *db =[DB Open]; Sqlite3_stmt*STMT =Nil; Student*student =Nil; intresult = SQLITE3_PREPARE_V2 (db,"SELECT * from Students where ID =?", -1, stmt, nil); if(Result = =SQLITE_OK) { //if a query statement or other SQL statement is conditional, inside the function that prepares the statement object, SQL uses t