Daily micro-tips for C#, SQL, performance, and scalable backend engineering.
SELECT DISTINCT schema_name(fk_tab.schema_id) + ‘.’ + fk_tab.name as foreign_table, ‘>-‘ as rel, schema_name(pk_tab.schema_id) + ‘.’ + pk_tab.name as primary_table FROM sys.foreign_keys fk INNER JOIN sys.tables fk_tab on fk_tab.object_id = fk.parent_object_id INNER JOIN sys.tables pk_tab on pk_tab.object_id = fk.referenced_object_id WHERE pk_tab.[name] = ‘Your table’ — enter table name here — and schema_name(pk_tab.schema_id) = ‘Your table schema […]
–View the current value: DBCC CHECKIDENT (“{table name}”, NORESEED) –Set it to the max value plus one: DBCC CHECKIDENT (“{table name}”, RESEED) –Set it to a spcefic value: DBCC CHECKIDENT (“{table name}”, RESEED, {New Seed Value})
CREATE TABLE #tmpTable ( COL1 int, COL2 int, COL3 nvarchar(max), COL4 nvarchar(max), COL5 bit ) INSERT INTO #tmpTable exec SpGetRecords ‘Params’ NOTE: The columns of #tmpTable must be the same as SpGetRecords. Otherwise, there will be a problem. If there are no parameters in the stored procedure, you don’t need to use ‘Params’.
The OUTPUT clause was introduced in SQL Server 2005. The OUTPUT clause returns the values of each row that was affected by an INSERT, UPDATE, or DELETE statement. It even supports a MERGE statement, which was introduced in SQL Server 2008 version. The OUTPUT clause has access to two temporary or in-memory SQL tables, INSERTED […]
If you have two tables A and B, both with column C, here are the records, which are present in the table A but not in B: SELECT A.* FROM A LEFT JOIN B ON (A.C = B.C) WHERE B.C IS NULL To get all the differences with a single query, a full join must be used, like this: […]
var table = $(“#datatable”).DataTable({ “paging”: false, “ordering”: false, “searching”: false, “info”: false });
In SQL Server 2012+, you can use OFFSET…FETCH. The below query will help you to get 2nd row. But with little changes, you can get the ‘n’th row as well. SELECT <column(s)> FROM <table(s)> ORDER BY <sort column(s)> OFFSET 1 ROWS — Skip this number of rows FETCH NEXT 1 ROWS ONLY; — Return this […]
When working with Code First Migrations, developers often struggle with setting default values at the database level. While you can set a default value in your C# class, doing it directly in the SQL schema is much more robust. Here is how you can achieve this using defaultValue and defaultValueSql. 1. Using Static Default Values […]
visibility: hidden (Hide but keep the space) <div stlye=”visibility: hidden;”>The Components We want to Hide</div> By default, the value of the visibility property is visible. However, if you want to make an image invisible, you can set the value of visibility to hidden. display: none (Hide and remove the space) <div stlye=”display: none;”>The Components We want to Hide</div> The display […]
SELECT (SCHEMA_NAME(A.schema_id) + ‘.’ + A.Name) AS TableName , SUM(B.rows) AS RecordCount FROM sys.objects A INNER JOIN sys.partitions B ON A.object_id = B.object_id WHERE A.type = ‘U’ GROUP BY A.schema_id, A.Name ORDER BY RecordCount DESC
If you are working with DataTables, you’ve likely encountered that frustrating moment: your data changes in the database, but your table refuses to refresh. You call table.ajax.reload(); and… nothing happens, or worse, you get a console error. Let’s break down why this happens and how to fix it with a single line of code. 1. […]
When working with DataTables over multiple pages it is often useful to set the initialisation defaults to common values (for example you might want to set dom to a common value so all tables get the same layout). This can be done using the $.fn.dataTable.defaults object. This object will take all of the same parameters as the DataTables initialisation […]
Creating Local Temp Table [with #]: SELECT TOP(10) ID INTO #TempTable FROM MyTable Craeting Global Temp Table [with ##]: SELECT TOP(10) ID INTO ##TempTable FROM MyTable Reaching Local Temp Table with Query: SELECT name FROM tempdb..sysobjects WHERE name LIKE ‘#TempTable%’
To calculate the sum of a column in a DataTable use the DataTable.Compute method. DataTable dt; … int sumValue; sumValue = dt.Compute(“Sum(TheSumColumn)”, string.Empty);
dataTable.DefaultView.ToTable(true, “target_column”); first parameter in ToTable() is a boolean which indicates whether you want distinct rows or not. second parameter in the ToTable() is the column name based on which we have to select distinct rows. Only these columns will be in the returned datatable. If you need to get distinct based on two columns: dataTable.DefaultView.ToTable(boolean, params string[] columnNames)
EXEC sp_fkeys ‘TableName’ You can also specify the schema: EXEC sp_fkeys @pktable_name = ‘TableName’, @pktable_owner = ‘dbo’
These 2 scripts clean all views, SPS, functions PKs, FKs and tables. 1. The First script by Adam Anderson, updated to support objects in other schemas than dbo: — check constraints select @stmt = isnull( @stmt + @n, ” ) + ‘alter table [‘ + schema_name(schema_id) + ‘].[‘ + object_name( parent_object_id ) + ‘] drop […]
You can check the example code:
If there is no default value for the column then you can use this query: ALTER TABLE MyTable ADD CONSTRAINT df_MyTable_MyColumn DEFAULT 0 FOR MyColumn