You cannot access directly an sql server from your pcl project in Xamarin.Forms because System.Data.SqlClient is not available on pcl. But you can do it through a dependency service. First in you PCL project declare you service public interface IDbDataFetcher { string GetData(string conn); } Then on you Android project implement the service interface [assembly: … Read more
Open the XML view of .jrxml file. Then find code similar to this <field name=”image” class=”java.lang.Object”/> /* “image” must be replaced by your actual field name */ and change it to <field name=”image” class=”java.io.InputStream”/>
SELECT document_id FROM table WHERE tag = ‘tag1’ OR tag = ‘tag2’ GROUP BY document_id HAVING COUNT(DISTINCT tag) = 2 Edit: Updated for lack of constraints…
If your database allows expressions in an index you can do something like this (ANSI SQL): CREATE UNIQUE INDEX on your_table (least(column1, column2) , greatest(column1, column2)); Note this is a unique index not a unique constraint. The only difference for most DBMS is that you can’t have a unique index as the target of a … Read more
Here is the first part: Overlapping cars per user… SQLFiddle – correlated Query and Join Query Second part – more than one user in one car at the same time: SQLFiddle – correlated Query and Join Query. Query below… I use the correlated queries: You will likely need indexes on userid and ‘car’. However – … Read more
I just had to deal with the same error message, thrown by DriverManager.getConnection(URL,username,password). I even got the same “magic numbers” (4739923 > 1048576); googling for those “magic numbers” will show results from people also getting the error thrown by some DriverManager.getConnection statement. In my case, the error message about packet size was COMPLETELY MISLEADING; I … Read more
PDO If you want to interface with an MS Access database using PHP, PDO is available for you. <?php try { $pdo = new PDO(“odbc:Driver={Microsoft Access Driver (*.mdb)};Dbq=C:\accounts.mdb;Uid=Admin”); } catch (PDOException $e) { echo $e->getMessage(); } When using PDO, due to the unified interface for DB operations, you have the opportunity to make your app … Read more
The likely reason you are seeing a blank DataGridView is due to your filter string searching for exact matches to the TextBox text. “Name=”{0}”” Because you are updating this filter in the TextBox.TextChanged event, the first time you enter a character – no matches are found. For example, given the following grid: ╔════╦══════╗ ╔════════╗ ║ … Read more
Here are some scripts I wrote for reverse engineering SQL server schemas. They may be of some use. Also, as a general interest they give some examples of how to get various bits of information out of the data dictionary. I’ve added an MIT license below to make permission-to-use explicit and for some basic no-implicit-warranty … Read more
You can still use key if you want to. Just wrap it with backtick, CREATE TABLE IF NOT EXISTS users ( `key` INT PRIMARY KEY NOT NULL AUTO_INCREMENT, username VARCHAR(50) NOT NULL, ); but as an advise, refrain from using any reserved keyword to avoid future problems. 🙂 MySQL Reserved Keywords List