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SQL, stands for structured query language, is a domain-specific declarative programming language based on tuple relational calculus and relational algebra. It is used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS). RDBMS is a relational database management…

SQL consists of many types of statements which are classified in five types of sub-languages- Data Definition Language (DDL): to create and modify the structure of the database. All the commands of DDL are auto-committed which means it permanently saves all the changes in the database.DDL Commands: Data Manipulation Language (DML): DML commands are used…

To create a database in SQL the CREATE DATABASE statement is used. The database name should be unique and less than 128 characters. To create a database in SQL and SQL Server use the command- CREATE DATABASE database_name; Example- CREATE DATABASE student_db; To view database in SQL use command- SHOW DATABASE; To Create or Replace…

DROP DATABASE   To drop an existing SQL database use command- DROP DATABASE database_name; HOW TO DROP DATABASE IN T-SQL DROP DATABASE [IF EXISTS] database_name(s); Example- DROP DATABASE [ IF EXISTS] database_name1 , database_name2, database_nameN; Note- We are required to keep a database backup if we need to recover it in the future. We are…

CREATE TABLE CREATE TABLE statement is used to create a new table in the database. A table definition consists of the table name, a list of columns, their data types, default values, and any integrity constraints as shown in below SQL server syntax – CREATE TABLE <table_name1> ( <column_name1> <data_type> <default_value> <identity_specification> <column_constraint>, <column_name2> <data_type>…

DROP TABLE, TRUNCATE TABLE AND DELETE IN SQL Key Word Syntax Explanation DROP TABLE DROP TABLE <table_name>; DROP TABLE is used to delete a table definition and all data from a table TRUNCATE TABLE TRUNCATE TABLE <table_name>; TRUNCATE TABELE is used to remove all rows or complete data from a table. It doesn’t delete the…

ALTER TABLE IN SQL ALTER TABLE statement is used to add, delete, or modify columns and add or drop constraints on existing table. ALTER TABLE- ADD COLUMN Syntax- ALTER TABLE <table_name> ADD <column_name> <datatype>; Example- Following SQL will add DOB column to existing msstudentsnew table- ALTER TABLE msstudentsnew ADD DOB date; ALTER TABLE – ALTER…

INSERT INTO INSERT INTO statement is used to insert values or records into table in SQL. Records in a table can be added by specifying both the column names and their values that need to be updated. Syntax- INSERT INTO <table_name>(column1, column2, column3, …) VALUES (value1, value2, value3, …); Records in a table can also…

UPDATE UPDATE statement is used to update the existing records in a table in SQL. Syntax- UPDATE <table_name> SET column1 = value1, column2 = value2, … WHERE <condition>; Example- UPDATE mstudentsnew SET st_name = ‘Ajai’ WHERE st_id = 1; Note- IF WHERE Clause is not used it will update all the records.

SELECT SELECT statement is used to access records from a database. The table which stores the record returned by the SELECT statement is called a result-set table. Syntax- SELECT column_name1, column_name2, …column_nameN FROM <table_name>; Description- The column_name1, column_name2, …column_nameN are the name of those columns in the table whose data we want to read or access. Syntax-…

SELECT DISTINCT The SQL DISTINCT command is used with SELECT key word to retrieve only distinct or unique values. Syntax- SELECT DISTINCT column_name1, column_name2, …column_nameN FROM <table_name>; Description- The distinct values from column_name1, column_name2, …column_nameN will be retrieved. It will avoid duplicate data.