Creation and management of SQL databases

CREATE DATABASE statement in SQL

CREATE DATABASE, is the DDL statement, which allows us to create databases within our management system. In this section we will learn how to create a specific database, both by SQL commands and by the graphical editing tool

CREATE SCHEMA statement in Transact SQL

CREATE SCHEMA is the DDL statement that enables us to create a new schema in a new database. In this section we will see what a schema is, the system's default schemas, how to create them and grant them permissions

CREATE TABLE statement in SQL

CREATE TABLE, is the DDL statement that allows you to create tables in a specific database. In this section we will see how to declare the columns along with the data type, properties and restrictions when executing the statement.

ALTER TABLE statement in SQL

ALTER TABLE is the DDL statement to add, remove or modify columns in a table, as well as to add or remove constraints on it. In this section we will see graphically and with examples, how to use this sentence

Indexes in SQL: CREATE INDEX

An index lets the database find rows without scanning the whole table. We will see how to create indexes with CREATE INDEX, the difference between clustered and nonclustered, unique and composite indexes, and when not to create them

Runnable examples

DROP TABLE statement in SQL

DROP TABLE is the DDL statement to drop tables along with all their data, indexes, triggers, constraints, and permissions

INSERT INTO statement in SQL

INSERT INTO is the DML statement for inserting records into database tables. In this section we will see how to apply the sentence, taking into account the nature of the data, properties and restrictions in handling the information

Statement BULK INSERT in Transact SQL

BULK INSERT is the DML statement that allows you to insert records into a table or view from an external file, usually a CSV file

UPDATE statement in SQL

UPDATE is the DML command that allows you to update database records. In other words, UPDATE allows you to modify the values of the columns of the tables respecting the corresponding data type

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DELETE statement in SQL

DELETE is the DML command to delete records from database tables. In its execution, it is very important to take into account the WHERE clause, to prevent the changes from being propagated and all the records from the table being deleted

Runnable examples

TRUNCATE TABLE statement in SQL

TRUNCATE TABLE is the DML statement that allows you to delete all the data from a table without affecting its schema and structure. Unlike the DELETE FROM statement, TRUNCATE TABLE does not allow the WHERE clause to be used

GRANT and REVOKE statements in Transact SQL

DCL (Data Control Language) is the language in charge of managing access to the database and its contents, mainly through the GRANT statements (to grant permissions) and REVOKE (to eliminate existing permissions.