SQL Commands
- DDL (Data Definition Language)
- DML (Data Manipulation Language)
- DCL (Data Control Language)
- DQL (Data Query Language)
The SQL Sum() function is an aggregate function in SQL that returns the total values of an expression. The expression may be numerical, or it may be an expression. Syntax: SELECT SUM(columnname)...
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Codd’s Rules Dr. Edgar F. Codd, in 1985, laid down 13 fundamental rules after doing large-scale research on the Relational Model of databases. According to him, every database must follow these...
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As a beginner, one does not focus much on Formatting the queries while writing their code. This leads to a great confusion while referring the code in future. For a...
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The SQL Right Join query displays all the table records and similar records from the left table. The query display zero records if it doesn’t find any similar records. If...
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How to Add Comments in SQL Comments are text notes that are incorporated into the program to make the code easier to understand. In SQL, commenting is used to explain various sections...
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In this article, we will learn and understand the Drop and Truncate commands and the difference between these two commands. What is Drop Command? Drop is a Data Definition Language command in...
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This article will deal with a new insertion method in SQL which inserts multiple rows at a time. Multiple records can be inserted at a time into a specific table with...
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Introduction To delete or remove the unused/unwanted rows from a table, DELETE command is used in SQL.DELETE command removes the entire record from a table.The DELETE statement can delete one or...
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SQL injection is a technique, this may destroy the database. It is one type of hacking technique. SQL IN WEB PAGES: Injection occurs when we ask for input like an id or...
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SQL Aliases: These are used to give a temporary name for a column or table. These are used to make tables or columns more readable. These are used to rename the table...
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The most common and important question asked in interviews that how we can find the Nth highest salary in a table (2nd highest salary, 3rd highest salary, or Nth highest...
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The SQL Max() function is an aggregate function in SQL. This function returns the values which are greater in the condition. The condition may be a number, or it may...
5 minutes read.
In this tutorial, we will learn how to copy tables in SQL with the help of examples. Using the SELECT INTO statement in the SQL we can copy one table into...
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In Structured Query Language, if you want to add columns in an existing table, then modify the table, or delete columns from the table. All these operations are allowed only...
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How to use COUNT in SQL Introduction COUNT( ) is an aggregate function in SQL.This function counts the number of records in a table if the condition is not specified.If the condition...
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TEACHER Table LCASE() Function The LCASE() function is used to return lower case values of specified column. Syntax: Select Lcase(column_name) from table_name; Example: Select Lcase(teacher_name) from teacher; Syntax: Select Lcase(column_name) from table_name [where condition]; Example: Select Lcase(teacher_name) from teacher where teacher_id=1; UCASE() Function The UCASE()...
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SQL TABLE Structured Query Language (SQL) is a relational database (RDBMS) where data is stored in the form of tables, that is, in rows and columns. These tables are known as...
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Introduction In SQL, sometimes it is required to delete a column of a table.The use of ALTER TABLE command with DROP COLUMN clause will serve the purpose to delete/remove a column...
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In this topic, we will learn how to add multiple conditions using the WHERE clause. First, let's understand the concept of WHERE clause. WHERE clause is used to specify a condition while...
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The GROUP BY clause is used to arrange similar records into the groups in the Structured Query Language queries. The records are arranged with the help of functions which is...
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