(SQL Example for Citizen Data Scientist & Business Analyst) SQL | LIKE 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 with the letter ‘y’, or start with ‘b’ and end with ‘l’, or even more complicated and …
Day: February 3, 2021
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | LIMIT Clause 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 time. The LIMIT clause is used to set an upper limit on the number of tuples …
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | Join (Cartesian Join & Self Join) In this article, we will discuss about the remaining two JOINS: CARTESIAN JOIN SELF JOIN Consider the two tables below: StudentCourse CARTESIAN JOIN: The CARTESIAN JOIN is also known as CROSS JOIN. In a CARTESIAN JOIN …
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | ALTER (ADD, DROP, MODIFY) 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 the existing table. ALTER TABLE – ADD ADD is used to add columns into …
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | CREATE There are two CREATE statements available in SQL: CREATE DATABASE CREATE TABLE CREATE DATABASE A Database is defined as a structured set of data. So, in SQL the very first step to store the data in a well structured manner is to create …
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | ALTER (RENAME) 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 the name of table. *Syntax may vary in different databases. Syntax(Oracle,MySQL,MariaDB): ALTER TABLE table_name RENAME TO new_table_name; Columns …
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | DROP, TRUNCATE DROP DROP is used to delete a whole database or just a table.The DROP statement destroys the objects like an existing database, table, index, or view. A DROP statement in SQL removes a component from a relational database management system (RDBMS). Syntax: …
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | Create Table Extension SQL provides an extension for CREATE TABLE clause that creates a new table with the same schema of some existing table in the database. It is used to store the result of complex queries temporarily in a new table. The new table …
(SQL Example for Citizen Data Scientist & Business Analyst) SQL | SELECT Query Select is the most commonly used statement in SQL. The SELECT Statement in SQL is used to retrieve or fetch data from a database. We can fetch either the entire table or according to some specified rules. The data returned is …