iOS使用SQLite编程

最新推荐文章于 2025-05-16 14:24:17 发布

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本文介绍如何使用Objective-C结合SQLite进行本地数据存储操作，重点演示了查询SQLite数据库的具体步骤，包括数据库打开、SQL语句准备及执行、结果集读取等。

因为自己以前接触过SQL Server，基于SQL命令的相同，所以就选择SQLite做本地存储，而没有用coreData、XML/plist、或其他什么？

先要导入Framework库：libsqlite3.0.dylib，头文件调用#import <sqlite3.h>，再定义个全局变量sqlite3 *database 作为数据库对象。准备工作完成！

核心代码如下，了解Sql的人同能理解什么意思。

1   -(void) QueryTable;
2   {
3        // Setup the database object
4        sqlite3 *database;
5        catalogMenus = [[NSMutableArray alloc] init];
6        // Open the database from the users filessytem
7        if(sqlite3_open([[appDelegate getDBPath:dbName] UTF8String], &database) == SQLITE_OK)
01            // Setup the SQL Statement and compile it for faster access
02            const char *sqlStatement = “select * from table_catalogs”;
03            sqlite3_stmt *compiledStatement;
04            if(sqlite3_prepare_v2(database, sqlStatement, -1, &compiledStatement, NULL) == SQLITE_OK)        // Loop through the results and add them to the feeds array
05            while(sqlite3_step(compiledStatement) == SQLITE_ROW) {
06               // Read the data from the result row
07               NSMutableString *ID = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 0)];
08               NSMutableString *name = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 1)];
09               NSMutableString *pic = [NSString stringWithUTF8String:(char *)sqlite3_column_text(compiledStatement, 2)];
10
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01               // add catalog to menus
02               Category *catalog = [Category catalogsWithUID:ID name:name thumb:pic];
03              [catalogMenus addObject:catalog];
04            }
05        }
06        // Release the compiled statement from memory
07        sqlite3_finalize(compiledStatement);
08   }
09        // Important To Print Out Values for Objects
10        for (Category *itm in catalogMenus)
11       {
12         NSLog(@”id:%@, name:%@”,itm.categoryID, itm.categoryName);
13       }
14        NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@”id” ascending:YES];
15        NSArray *sortDescriptors = [NSArray arrayWithObject:sortDescriptor];
16        NSArray *sortedArray = [catalogMenus sortedArrayUsingDescriptors:sortDescriptors];
17        catalogMenus = [sortedArray mutableCopy];
18
19        sqlite3_close(database);
20   }