SQL

In certain Structured Query Language (SQL) statements, WHERE clauses can be used to limit what rows the given operation will affect. SQL allows users to retrieve granular result sets by providing a variety of different types of predicates, each of which use a specific operator to evaluate rows. This guide will outline two types of predicates: range predicates which use the BETWEEN operator, and set membership predicates which use the IN operator.

In certain Structured Query Language (SQL) statements, WHERE clauses can be used to limit what rows the given operation will affect. SQL allows users to retrieve granular result sets by providing a variety of different types of predicates, each of which use a specific operator to evaluate rows. This guide will outline two types of predicates and the operators they use: comparison operators and the IS NULL operator.

SQL provides a great deal of flexibility in terms of how it allows you to insert data into tables. You can specify individual rows of data with the VALUES keyword, copy entire sets of data from existing tables with SELECT queries, as well as define columns in ways that will cause SQL to insert data into them automatically. In this guide, we’ll go over how to employ each of these methods to load tables with data using SQL’s INSERT INTO syntax.

When working with a database, there may be times when you need to change data that’s already been inserted into it; you may need to correct a misspelled entry, or perhaps you have information to add to an incomplete record. SQL provides the UPDATE statement which allows users to change existing data in a table. This guide outlines how you can use SQL’s UPDATE syntax to change data in one or more tables. It will also explain how SQL handles UPDATE operations that conflict with foreign keys.

In Structured Query Language (SQL), a “view” is a virtual table whose contents are the result of a specific query to one or more tables. This guide provides an overview of what SQL views are and why they can be useful. It also highlights how you can create, query, modify, and destroy views using standard SQL syntax.

Many database designs separate information into different tables based on how certain data points relate to one another. Even in cases like this, it’s likely that there will be times when someone will want to retrieve information from more than one table at a time. A common way of accessing data from multiple tables in a single SQL operation is to combine the tables with a JOIN clause. This guide outlines how to retrieve data from multiple tables by joining them together.