Join operations in SQL

When we want to make relations between two or more tables, we take in use join operations. We are going to understand these operations with example, so first, we will create a database, table, and then insert some data in it. Database Name – jai_school Query– Create two tables – admission and fee admission table … Read more

HAVING clause in SQL

HAVING clause is used to filter out records based on aggregated values. In the respect of aggregation, WHERE can’t be used. It does not work. Therefore, while applying condition where we are calculating fields data, we will use HAVING. See below example-

SQL length() function

SQL length() function:- We use this to display data from a table according to the length of the values stored in the table’s cell. For example, If I want to retrieve data with length 3 from a column then I will use query – SELECT * FROM table WHERE length(column) < 4; This function applies … Read more