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Category Archives: SQL

Sometimes we may want to rename our table to give it a more relevant name. For this purpose we can use ALTER TABLE to rename… Read More
ALTER TABLE is used to add, delete/drop or modify columns in the existing table. It is also used to add and drop various constraints on… Read More
If there are a large number of tuples satisfying the query conditions, it might be resourceful to view only a handful of them at a… Read More
We know that a primary key of a table cannot be duplicated. For instance, the roll number of a student in the student table must… Read More
Sometimes we may require tuples from the database which match certain patterns. For example, we may wish to retrieve all columns where the tuples start… Read More
SQL | ALL and ANY SOME operator evaluates the condition between the outer and inner tables and evaluates to true if the final result returns… Read More
OFFSET and FETCH Clause are used in conjunction with SELECT and ORDER BY clause to provide a means to retrieve a range of records. OFFSET… Read More
BETWEEN The SQL BETWEEN condition allows you to easily test if an expression is within a range of values (inclusive). The values can be text,… Read More
The SQL WITH clause was introduced by Oracle in the Oracle 9i release 2 database. The SQL WITH clause allows you to give a sub-query… Read More
In SQL, EXCEPT returns those tuples that are returned by the first SELECT operation, and not returned by the second SELECT operation. This is the… Read More
LISTAGG function in DBMS is used to aggregate strings from data in columns in a database table. It makes it very easy to concatenate strings.… Read More
SQL injection is a code injection technique, used to attack data driven applications, in which malicious SQL statements are inserted into an entry field for… Read More
What is SQL? SQL stands for Structured Query Language. It is a language used to interact with the database, i.e to create a database, to… Read More
For doing operations on data sql has many built-in functions, they are categorised in two categories and further sub-categorised in different seven functions under each… Read More
In SQL, dates are complicated for newbies, since while working with database, the format of the date in table must be matched with the input… Read More