Encapsulation of SQL statements

//

Sqlmanager.m

0427Ibook

//

Created by jerehedu on 15/4/29.

Copyright (c) 2015 jerehedu. All rights reserved.

//

#import "SqlManager.h"

#import "Book.h"

@implementation Sqlmanager

/**

* Get Links

* @return Linked objects

*/

+ (Sqlite3 *) getconn{

0 defining links

Static Sqlite3 * SQLite;

if (Sqlite==nil) {

1> get the Sandbox documents path

NSString * PATH=KPATH;

NSLog (@ "%@", Kpath);

Path =[path stringbyappendingpathcomponent:@ "Book.sqlite"];

2> If the file exists, open the link directly if it does not exist and open

if (Sqlite_ok==sqlite3_open (path. Utf8string, &sqlite)) {

NSLog (@ "create success");

}else{

NSLog (@ "Create failed");

}

}

return sqlite;

}

/**

* EXECUTE statement

*

* SQL executed @param sql

* Tips for @param tips

*

* @return is successful

*/

+ (BOOL) EXEC: (NSString *) SQL Withtips: (NSString *) tips{

1 Getting Links

Sqlite3 * Sqlite=[sqlmanager Getconn];

2 EXECUTE statement

Char *errmsg;

if (sqlite_ok==sqlite3_exec (SQLITE, SQL. Utf8string, nil, nil, &errmsg)) {

NSLog (@ "%@ success", tips);

return YES;

}else{

NSLog (@ "%@ failed, Reason%s", tips,errmsg);

return NO;

}

}

/**

* Check out people information

*

* @param SQL < #sql description#>

*

* @return < #return value description#>

*/

+ (Nsarray *) Getallbookwithsql: (NSString *) sql{

1 Getting Links

Sqlite3 * Sqlite=[sqlmanager Getconn];

2 Querying data

Nsmutablearray *array=[nsmutablearray Array];

Sqlite3_stmt *stmt;

if (sqlite_ok== sqlite3_prepare_v2 (SQLITE, SQL. Utf8string,-1, &stmt, nil)) {

Iterate through the current result set and take out the data

while (Sqlite3_step (stmt) ==sqlite_row) {

Extracting result set data

int bookid= sqlite3_column_int (stmt, 0);

Const unsigned char * bookname= sqlite3_column_text (stmt, 1);

Const unsigned char * summary= sqlite3_column_text (stmt, 2);

int readnum= sqlite3_column_int (stmt, 3);

int doller= sqlite3_column_int (stmt, 5);

Const unsigned char * writer= sqlite3_column_text (stmt, 4);

Const unsigned char * bookpic= sqlite3_column_text (stmt, 6);

Putting the result set data into an array

Book *book=[[book alloc] init];

Book.book_id=bookid;

Book.book_name=[nsstring stringwithutf8string: (const char *) BookName];

Book.summary=[nsstring stringwithutf8string: (const char *) summary];

Book.book_pic=[nsstring stringwithutf8string: (const char *) BOOKPIC];

Book.writer=[nsstring stringwithutf8string: (const char *) writer];

Book.doller=doller;

Book.read_num=readnum;

[Array Addobject:book];

}

}else{

NSLog (@ "Query failed");

}

return array;

}

/**

* Judgment is not there

*

* @param SQL < #sql description#>

*

* @return is present

*/

+ (BOOL) Isexistwithsql: (NSString *) sql{

1 Getting Links

Sqlite3 * Sqlite=[sqlmanager Getconn];

2 Querying data

Sqlite3_stmt *stmt;

if (sqlite_ok== sqlite3_prepare_v2 (SQLITE, SQL. Utf8string,-1, &stmt, nil)) {

Iterate through the current result set and take out the data

while (Sqlite3_step (stmt) ==sqlite_row) {

Extracting result set data

int count= sqlite3_column_int (stmt, 0);

Return count>0;

}

}else{

NSLog (@ "Query failed");

}

Sqlite3_finalize (stmt);

return NO;

}

/**

* Get account information

*

* @return < #return value description#>

*/

+ (NSString *) getaccount{

Writes the logged in person information to the sandbox

NSString *path=[kpath stringbyappendingpathcomponent:@ "User.tt"];

Nsfilemanager * Manager =[nsfilemanager Defaultmanager];

NSData * Data=[manager Contentsatpath:path];

NSString * account=[[nsstring alloc] Initwithdata:data encoding:nsutf8stringencoding];

return account;

}

+ (void) closeconn{

Sqlite3 * Sqlite=[sqlmanager Getconn];

Sqlite3_close (SQLite);

Sqlite=nil;

}

@end

Encapsulation of SQL statements