Ios-senior19-fmdb third-party applications

Code Edition

First step: Introduce the framework and introduce the Support class library (libsqlite3.0 Add)

#import <FMDB.h>

Declaring database objects

@property (Nonatomic,strong) fmdatabase *database;

Storage path

@property (Nonatomic,strong) NSString *filepath;

############## #创建表 ######################

-(void) CreateTable {

First step: Create SQL statements

NSString *createsql = @ "CREATE table if not exists t_student (ID integer primary key autoincrement not null,name text not n Ull,age integer not null,sex text not null) ";

Step two: Find the storage path

NSString *document = [Nssearchpathfordirectoriesindomains (nsdocumentdirctory,nsuserdomainmask,yes) objectAtIndex:0 ];

NSLog (@ "document =%@", document);

Self.filepath = [Document stringbyappendingpathcomponent:@ "Student.sqlite"];

Step three: Initialize the Fmdb object with a path

Self.database = [Fmdatabase DatabaseWithPath:self.filePath];

Fourth step: (Database execution related operations) need to determine the database opened when the execution of the statement

if ([Self.database open]) {

BOOL result = [Self.database executeupdate:createsql];

if (result) {

NSLog (@ "Build table success");

}else {

NSLog (@ "Build table failed");

}

}

Fifth step: Close the database

[Self.database Close];

}

########### #添加数据 ####################

Open Database

[Self.database Open];

Step two: Make the relevant operation

Nsarray *namearray = [Nsarray arraywithobjects: @ "Mbboy" @ "Boom Sky" @ "Xiao Ming"];

for (int i = 0; I <nameArray.count; i++) {

NSString *name = [NameArray objectatindex:i];

Insert statement

NSString *insertsql = @ "INSERT into t_student (name,age,sex) VALUES (?,?,?)";

BOOL result = [Self.database executeupdate:@ "INSERT into t_student (name,age,sex) VALUES (?,?,?)", name,@ "a", @ "boy"];

if (result) {

NSLog (@ "Insert success");

}else {

NSLog (@ "Insert failed");

}

Close the database

[self.database close];

}

############# #更改数据 ######################

Open Database

[Self.database];

Change the name for Mbboy.

BOOL result = [Self.database executeupdate: @ "Update t_student set name =? WHERE name =?", @ "Menglingxu", @ "Mbboy"];

if (result) {

NSLog (@ "Change succeeded");

} else {

NSLog (@ "Change failed");

}

Close the database

[Self.database Close];

}

############# #删除数据 #######################

Open Database

[Self.database Open];

EXECUTE statement

BOOL result = [self.database executeupdate:@ "delete from t_student where name =?", @ "Menglingxu"];

if (result) {

NSLog (@ "Delete succeeded");

}else {

NSLog (@ "Delete failed");

}

[Self.database Close];

################## #查询数据 ###################

Open Database

[Self.database Open];

Query the class used for the current result Fmresultset

Fmresultset *resultset = [self.database executeQuery: @ "Select *from t_student"];

Iterate through the desired result content

while ([ResultSet next]) {

nssting *name = [ResultSet objectforcolumnname: @ "name"];

Nsinteger age = [ResultSet intforcolumn:@ ' age '];

NSString *sex = [resultSet objectforcolumnname:@ "sex"];

}

Close the database

[Self.database Close];

}

############# #插入很多学生 ####################

Adding data as a queue is a common way to add Fmdb

Fmdb does not support simultaneous operation of multiple threads, all of which typically implement related operations serially

[Self.database Open];

First step: Create an action queue

Fmdatabasequeue *queue = [Fmdatabasequeue DatabaseQueueWithPath:self.filePath];

Identity: Record whether the operation was successful

__block BOOL issucceed = YES;

Step Two: Package the required events in the operations queue

[Queue intransaction:^ (Fmdatabase *db, BOOL *rollback) {

Serial queue

Issucceed = [db executeupdate:@ "insert into t_student (name, age, Sex) VALUES (?,?,?)", @ "Old King next Door" @ "@" @ "Nan"] && Issucceed;

Issucceed = [db executeupdate:@ "insert into t_student (name, age, Sex) VALUES (?,?,?)", @ "-1", @ "", @ "Unknow"] && Issucceed;

Issucceed = [db executeupdate:@ "insert into t_student (name, age, Sex) VALUES (?,?,?)" @ "ajar" @ "@" @ "Nan"] && Issucceed;

If there is an error, it will be returned

if (!issucceed) {

The parameters returned by the block rollback to be processed (a pointer of type bool).

*rollback = YES;

Return

}

}];

Close the database

[Self.database Close];

Ios-senior19-fmdb third-party applications