SQL Server query optimizer decides to use an index seek operator when the operator cost is low and it can easily find matching records using the B-Tree structure. An index seek operator provides significant performance gains. In the below picture, theEstimated Number of Rows to be Read...
"explicit value must be specified for identity column in table" error in SQL 2000 "FROM clause have the same exposed names. Use correlation names to distinguish them" "No transaction is active." error when trying to send a transactional SQL statment over MSDTC "Restricted data type attrib...
This code shows how to use Oracle's User Defined Types such asVARRAYusing ODP.NET in aWHEREclause of a query in an Oracle Stored Procedure. I am passing three parameters into my Oracle Stored Procedure: the first parameter is a UDTVARRAYasnumber(ParameterDirection.IN); the second parameter i...
COALESCE is one of the tools you have in SQL Server to work with NULL values. It may not be the first one you think of, but it can be a very good choice. In this tip I will provide examples of how you can use COALESCE to peacefully coexist with NULL values. Before we dig in to...
When referring to NULL within our data sets, we often use phrases such as “the NULL value” or “a value of NULL.” I do it all the time. I see it done all the time. Such phrases are so common that we think little of their use. But inherent in the p...
Supported Not supported WHERE MATCHHintsHints aren't supported.PredicatesSupported Not supported CONTAINS IS NULLSee alsoUse SQL to query dataFeedback Was this page helpful? Yes No Provide product feedback Additional resources Events Join us at FabCon Vegas Apr 1, 7 a.m. - Apr...
Anull valuein a database really means the lack of a value. It is a special “value” that you can’t compare to using the normal operators. You have to use a clause in SQL IS Null. On the other hand, an empty string is an actual value that can be compared to in a database. ...
Let's look at how to use the GROUP BY clause with the SUM function in SQL. Instead of writing the MongoDB query which is represented as a JSON-like structure 1 2 3 4 5 6 7 8 db.employees.aggregate([ { $group: { _id:"$department", ...
1. A function or operation is applied to a column Indexes aren’t used for a column that’s specified as a function’s argument, as shown in the following example: SQL SELECT*FROM[Employee]WHEREUPPER([State])='UT'SELECT*FROM[Employee]WHEREISNULL([IsActive],0)=1SELECT*FROM[Employee]WHER...
Once you have created all the necessary database objects, the next step is to load data into the tables. You can manually load data using the import functionality available in SQL Scripts. In the following exercise, you use SQL Scripts to load demonstration data....