MySQL | Group_CONCAT() Function
The GROUP_CONCAT() function in MySQL is used to concatenate data from multiple rows into one field. This is an aggregate (GROUP BY) function which returns… Read More »
Tag Archives: DBMS-SQL
MySQL | LEAD() and LAG() Function
The LEAD() and LAG() function in MySQL are used to get preceding and succeeding value of any row within its partition. These functions are termed… Read More »
MySQL | PARTITION BY Clause
A PARTITION BY clause is used to partition rows of table into groups. It is useful when we have to perform a calculation on individual… Read More »
Display Sequence of Numbers in SQL Using LEVEL
The term LEVEL refers to a Pseudocolumn in Oracle which is used in a hierarchical query to identify the hierarchy level (parent->child) in numeric format.… Read More »
Comparisons between DELETE vs DROP in SQL
Prerequisite – SQL Commands DELETE is a Data Manipulation Language (DDL) command and used when you want to remove some or all the tuples from… Read More »
Comparisons between SQL vs PLSQL
Introduction SQL: Structured Query Language (SQL) is a standard Database language which is used to create, maintain and retrieve the relational database. The advantages of… Read More »
Primary key Vs Unique key
Prerequisite – Keys in Relational Model A primary key is a column of table which uniquely identifies each tuple (row) in that table. Primary key… Read More »
Introduction of NewSQL | Set 2
Prerequisite – Introduction to NoSQL, Difference between SQL and NoSQL The term NewSQL is not exactly as wide as NoSQL. NewSQL systems all begin with… Read More »
Use of NoSQL in Industry
Prerequisite – Introduction to NoSQL, Difference between SQL and NoSQL Why NoSQL? In recent times you can easily capture and access data from various sources,… Read More »
SQL | Triggers
Trigger is a statement that a system executes automatically when there is any modification to the database. In a trigger, we first specify when the… Read More »
Difference between Where and Group By
Prerequisite – WHERE Clause, GROUP BY, Having vs Where Clause Where and Gropb By clauses are used to filter rows returned by the query based… Read More »
PL/SQL | User Input
Prerequisite – PL/SQL Introduction In PL/SQL, user can be prompted to input a value using & character. & can be used to prompt input for… Read More »
SQL Trigger | Book Management Database
Prerequisite – SQL Trigger | Student Database For example, given Library Book Management database schema with Student database schema. In these databases, if any student… Read More »
SQL Trigger | Student Database
Trigger: A trigger is a stored procedure in database which automatically invokes whenever a special event in the database occurs. For example, a trigger can… Read More »
CTE in SQL
The Common Table Expressions (CTE) were introduced into standard SQL in order to simplify various classes of SQL Queries for which a derived table was… Read More »