SQL 参考
Part II. The SQL Language

Part II. The SQL Language

This part describes the use of the SQL language in ProtonBase. We start with describing the general syntax of SQL, then explain how to create the structures to hold data, how to populate the database, and how to query it. The middle part lists the available data types and functions for use in SQL commands. The rest treats several aspects that are important for tuning a database for optimal performance.

The information in this part is arranged so that a novice user can follow it start to end to gain a full understanding of the topics without having to refer forward too many times. The chapters are intended to be self-contained, so that advanced users can read the chapters individually as they choose. The information in this part is presented in a narrative fashion in topical units. Readers looking for a complete description of a particular command should see Part IV.

Readers of this part should know how to connect to a ProtonBase database and issue SQL commands. Readers that are unfamiliar with these issues are encouraged to read Part I first. SQL commands are typically entered using the ProtonBase interactive terminal psql, but other programs that have similar functionality can be used as well.

Table of Contents

SQL Syntax

Lexical Structure

Value Expressions

Calling Functions

Data Definition

Table Basics

Default Values

Generated Columns

Constraints

System Columns

Modifying Tables

Schemas

Other Database Objects

Dependency Tracking

Data Manipulation

Inserting Data

Updating Data

Deleting Data

Returning Data from Modified Rows

Queries

Overview

Table Expressions

Select Lists

Combining Queries (UNION, INTERSECT, EXCEPT)

Sorting Rows (ORDER BY)

LIMIT and OFFSET

VALUES Lists

WITH Queries (Common Table Expressions)

Data Types

Numeric Types

Character Types

Binary Data Types

Date/Time Types

Boolean Type

Enumerated Types

Network Address Types

Bit String Types

UUID Type

JSON Types

Arrays

Object Identifier Types

Functions and Operators

Logical Operators

Comparison Functions and Operators

Mathematical Functions and Operators

String Functions and Operators

Binary String Functions and Operators

Bit String Functions and Operators

Pattern Matching

Data Type Formatting Functions

Date/Time Functions and Operators

Enum Support Functions

Network Address Functions and Operators

UUID Functions

JSON Functions and Operators

Sequence Manipulation Functions

Conditional Expressions

Array Functions and Operators

Aggregate Functions

Window Functions

Subquery Expressions

Row and Array Comparisons

Set Returning Functions

System Information Functions and Operators

System Administration Functions

Type Conversion

Overview

Operators

Functions

Value Storage

UNION, CASE, and Related Constructs

SELECT Output Columns