Querying Data with SQL
Having established the structure of relational databases using tables, rows, and keys, the next step is to learn how to access and manipulate the data stored within them. This chapter introduces Structured Query Language (SQL), the standard language designed specifically for this purpose.
You will learn the fundamental SQL commands required for basic data operations:
- Retrieving specific data from tables using the
SELECTstatement. - Filtering the retrieved data based on conditions using the
WHEREclause. - Sorting the results of your queries with
ORDER BY. - Adding new records into tables using the
INSERTstatement. - Modifying existing records within tables using the
UPDATEstatement. - Removing records from tables using the
DELETEstatement.
The focus is on understanding the syntax and application of these core commands, providing you with the ability to perform essential interactions with relational database data.
Sections
3.1 Introduction to Structured Query Language (SQL)
3.2 The SELECT Statement: Retrieving Data
3.3 Filtering Data with WHERE Clause
3.4 Sorting Results with ORDER BY
3.5 The INSERT Statement: Adding Data
3.6 The UPDATE Statement: Modifying Data
3.7 The DELETE Statement: Removing Data
3.8 Practice Writing Basic SQL Queries
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