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POImprove the performance of uitableview creation with many sections from sqlite database
 

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  1. POImprove the performance of uitableview creation with many sections from sqlite database
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    <p>This is my scenario:</p> <p>Sqlite database with 30000 products with 800 different brands.</p> <p>Table product is like this:</p> <pre><code>id | title | brand | other fields </code></pre> <p>Products example:</p> <pre><code>1221 | Product 1 | brand 1 | ... 1222 | Product 2 | brand 2 | ... 1223 | Product 3 | brand 2 | ... 1224 | Product 4 | brand 3 | ... 1225 | Product 5 | brand 3 | ... 1226 | Product 6 | brand 3 | ... </code></pre> <p>I need to create a uiviewtable with all products in different sections. Sections are different brands of products.</p> <p>I must implements this methods:</p> <pre><code>- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath </code></pre> <p>My idea to solve this problem is as follows (written in pseudocode):</p> <pre><code>NSArray * productList = [databaseManager getProductList]; //array with Product model objects NSArray * brandsList = [databaseManager getBrandsList]; NSMutableDictionary * dictionaryProductBrands = [NSMutableDictionary dictionaryWithCapacity:bramdsList.count]; for (NSString *brand in brandsList) { NSMutableArray *arrayProductsPerBrands = [NSMutableArray array]; for (Product *p in productList) { if ([p.brand isEqualToString:brand]) { [arrayProductsPerBrands addObject:p]; } } [dictionaryProductBrands setValue:arrayProductsPerBrands forKey:brand]; } </code></pre> <p>This solution has a poor performance.</p> <p>Can I improve the way to generate the tableview with sections with the same database?</p>
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    1. USmjimcua
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      1. USpreetam
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    1. COwhile fetching products use query `select * from productTable GroupBy brand` seems little more logical than yours....
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    2. COI need numberOfSectionsInTableView, numberOfRowsInSection and cellForRowAtIndexPath, how I can obtain this values with this select?
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    3. COI am saying just to append `group by` to your database query so that u will get a nit data. Rest of your logic will remain same
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      1. USpreetam
 

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A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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