- Practical PostgreSQL
- A Note Regarding Supplemental Files
- Preface
- I. Introduction & Installation
- 1. What Is PostgreSQL?
- 2. Installing PostgreSQL
- Preparing for Installation
- 10 Steps to Installing PostgreSQL
- Step 1: Creating the “postgres” User
- Step 2: Installing the PostgreSQL Source Package
- Step 3: Configuring the Source Tree
- Step 4: Compiling the Source
- Step 5: Regression Testing
- Step 6: Installing Compiled Programs and Libraries
- Step 7: Setting Environment Variables
- Step 8: Initializing and Starting PostgreSQL
- Step 9: Configuring the PostgreSQL SysV Script
- Step 10: Creating a Database
- II. Using PostgreSQL
- 3. Understanding SQL
- Introduction to SQL
- Introduction to Relational Databases
- SQL Statements
- Data Types
- Tables in PostgreSQL
- 4. Using SQL with PostgreSQL
- Introduction to psql
- Using Tables
- Adding Data with INSERT and COPY
- Retrieving Rows with SELECT
- A Simple SELECT
- Specifying Target Columns
- Expressions, Constants, and Aliases
- Selecting Sources with the FROM Clause
- Aliasing FROM Sources
- Removing Duplicate Rows with DISTINCT
- Qualifying with the WHERE Clause
- Joining Data Sets with JOIN
- Grouping Rows with GROUP BY
- Sorting Rows with ORDER BY
- Setting Row Range with LIMIT and OFFSET
- Comparing Sets with UNION, INTERSECT and EXCEPT
- Using Case Expressions
- Creating Tables from Other Tables
- Modifying Rows with UPDATE
- Removing Rows with DELETE
- Using Sub-Queries
- Using Views
- Further SQL Application
- 5. Operators and Functions
- 6. PostgreSQL Clients
- 7. Advanced Features
- Indices
- Advanced Table Techniques
- Arrays
- Automating Common Routines
- Transactions and Cursors
- Extending PostgreSQL
- Creating New Functions
- Creating New Operators
- Creating an operator
- Overloading an operator
- Dropping an operator
- III. Administrating PostgreSQL
- 8. Authentication and Encryption
- 9. Database Management
- 10. User and Group Management
- IV. PostgreSQL Programming
- 11. PL/pgSQL
- 12. JDBC
- 13. LXP
- V. Command Reference
- 14. PostgreSQL Command Reference
- Abort
- Alter Group
- Alter Table
- Alter User
- Begin
- Close
- Cluster
- Comment
- Commit
- Copy
- Create Aggregate
- Create Database
- Create Function
- Create Group
- Create Index
- Create Language
- Create Operator
- Create Rule
- Create Sequence
- Create Table
- Create Table As
- Create Trigger
- Create Type
- Create User
- Create View
- Current_Date
- Current_Time
- Current_Timestamp
- Current_User
- Declare
- Delete
- Drop Aggregate
- Drop Database
- Drop Function
- Drop Group
- Drop Index
- Drop Language
- Drop Operator
- Drop Rule
- Drop Sequence
- Drop Table
- Drop Trigger
- Drop Type
- Drop User
- DROP VIEW
- End
- Explain
- FETCH
- Grant
- Insert
- Listen
- Load
- Lock
- Move
- Notify
- Reindex
- Reset
- Revoke
- Rollback
- Select
- Select Into
- Set
- Set Constraints
- Set Transaction
- Show
- Truncate
- Unlisten
- Update
- Vacuum
- A. Multibyte Encoding Types
- B. Backend Options for postgres
- C. Binary COPY Format
- D. Internal psql Variables
- 14. PostgreSQL Command Reference
- E. About the Authors
- Index
- Colophon
- Copyright
- 3. Understanding SQL
Empties the contents of a table.
TRUNCATE [ TABLE ] namenameThe name of the table you wish to truncate. To truncate a table means to remove all rows from the table.
Use this command to remove all rows of a specified table. It does not scan through the
table before removing data, making it rather helpful when emptying large tables of data. In
essence, it is a quicker form of the DELETE command.
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