Imagine you are the head of a department in your company and want to find the list of unique names in your department. One way of doing this is by usingSQLqueries to create a list of unique names. SQL queries are the commands we use to get some information from a database. In this ...
Generally, it’s best practice to put unique constraints on a table to prevent duplicate rows. However, you may find yourself working with a database where duplicate rows have been created through human error, a bug in your application, or uncleaned data from external sources. This tutorial ...
Generally, it’s best practice to put unique constraints on a table to prevent duplicate rows. However, you may find yourself working with a database where duplicate rows have been created through human error, a bug in your application, or uncleaned data from external sources. This tutorial w...
One thing that is critical to understand is that query tuning is an iterative process. You won’t always get it right the first time and data access patterns may change over time. In terms of optimization, the first thing we want to do is get this query using an index and not using a...
The SQL ServerSQLSRV_01in the example has three (3) unique instances, twelve (12) databases total, four (4) responsible persons and five (5) applications linked to the databases. This is the summary of the sample data above. Applying this to the whole DBT database would prov...
“Unable to enlist in the transaction” with Oracle linked server from MS SQL Server [<Name of Missing Index, sysname,>] in non clustered index [Execute SQL Task] Error: The value type (__ComObject) can only be converted to variables of type Object. [ODBC Driver Manager] Data source ...
T-SQL GETDATE() ? ADD and SUBTRACT depending on the condition is CASE STATEMENT ADD COLUMN to variable table? Add prefix in data column Add Time in SQL HH:MM:SS to another HH:MM:SS Adding a column to a large (100 million rows) table with default constraint adding a extra column in...
Below is the description syntax of SQL select distinct multiple columns statement: Select:Using select, we can select the data as per the condition given in the query. For example, we can choose a distinct statement to retrieve unique records from the table. ...
Step 2: Find the Duplicates in MySQL To identify duplicates in MySQL, use queries that locate entries that appear multiple times. Depending on the use case and data complexity, there are several ways to find duplicates via queries. Option 1: GROUP BY and HAVING ...
With GROUP BY and HAVING, you can select distinct values based on group of columns. Where having can be used to find duplicate values also. Functionality-wise group by and distinct works similarly but group by also provide flexibility to use aggregate functions along with getting unique data. ...