Foreword is for water
SQL is also known as structured query language, and it is also a common language for interacting with current relational databases. Because of its concise syntax, convenient, practical and powerful functions, it has become the most widely used database language. Almost all important database management systems (DBMS) support SQL. Whether it is a person engaged in database-related work, or a program developer engaged in software, website development, etc., it is extremely necessary to learn and master SQL knowledge and be able to use SQL statements to manipulate various data, which is extremely necessary for developing applications. And database management work both play an important role.
From a practical point of view, "SQL Instant Check and Use" explains the basic concepts, common grammar and operation techniques of SQL from the shallower to the deeper. The book has 24 chapters, including simple data query, conditional query, fuzzy query, data filtering and data sorting, grouping, statistics, etc. It also includes sub-query, multi-table connection, data addition, deletion, modification, view, stored procedure, cursor , Transaction processing, and advanced technologies such as database and data table management. Including more than 200 SQL syntax, more than 200 application examples.
This book does not introduce the basic theory of database too much, but aims at first-line software developers, introducing the most commonly used and most necessary SQL knowledge in the actual working environment. In order to enable readers to use this book more conveniently and quickly retrieve the content that needs to be searched, it also provides: Common SQL knowledge points index and common SQL commands, common SQL functions appendix content. This book fully highlights the characteristics of example teaching, study integration, and follow-up investigation.
table of Contents:
Due to space limitations, I only show you the catalog and part of the content here. If you have a program that needs complete documentation (Yuan), you can help Sanlian, private message [information] or [directly add the assistant WeChat mxj94670 to get it for free
The main content of this book:
Chapter 1 Overview of SQL Language
This chapter mainly introduces some basic concepts about database and SQL language, and lays a good foundation for subsequent learning of SQL language.
Chapter 2 Simple Queries
This chapter will introduce the basic structure of SELECT statement, and how to use SELECT statement to complete simple query commands, so that readers have a simple understanding of SELECT statement.
Chapter 3 Calculated Column Queries
When using the SELECT statement to query, sometimes the column is calculated. For example, if you add or subtract these two columns, you will get a new column of data. This chapter will introduce the query of join column value, calculation query and query using expression.
Chapter 4 Conditional Query
When querying the data in the table, you often do not need all the data, you only need to query the data that meets your needs. When this happens, you can query the data by specifying the query conditions through the WHERE clause. For example, query data that meets the conditions of a given number.
Chapter 5 Range Query
Range query is used to query the data between two given values, usually BETWEEN.. AND and NOTBETWEEN..AND are used to specify range conditions.
Chapter 6 Filtering Data Using Logical Operators
If you want to combine several single conditions into a compound condition, you need to use logical operators NOT, AND and OR to complete the compound condition query. This chapter will introduce the method of using logical operators to query in the SELECT statement.
Chapter 7 Use the IN operator to filter data
When querying the data in the table, sometimes it is necessary to query data that meets one condition among multiple conditions. In this case, the OR operator can be used, but it is not convenient to use the OR operator for more conditions, such as , In the table to query the data of the provinces "Jilin Province", "Liaoning Province" and "Heilongjiang Province", using the OR operator will be more cumbersome. You can use the IN operator instead of the OR operator to complete the query task. This chapter will introduce the use of IN operator to readers through several typical examples.
Chapter 8 Formatting the Result Set
Formatting the result set uses some functions to format a column of data in the result set to facilitate users to view. For example, format the date in the result set, format the number of decimal places, and so on. This chapter will demonstrate how to format the result set through several examples.
Chapter 9 Fuzzy Query
When querying the data in the table, fuzzy query is often used. Fuzzy query can easily query relatively fuzzy data. For example, query data with the surname "Zhuge" in the name column, query data with "qq" in the user mailbox column, etc. This chapter will introduce the use of fuzzy query to readers through several typical examples.
Chapter 10 Row Data Filtering
When querying a data table, sometimes it is necessary to query a row of data in the table, or process the empty values in the table. This chapter will introduce some more complex queries in SQL. Including row query and null value judgment. Through the study of this chapter, readers will have a deeper understanding of data query.
Chapter 11 Data Sorting
Range query is used to query the value between two given values, usually use BETWEEN... AND and NOT... BETWEEN.. AND to specify the range conditions.
Chapter 12 Statistical Analysis of Data
This chapter will in-depth study the methods of statistical analysis of data through SQL statements. This chapter mainly learns how to use COUNT) function, SUM) function, AVG() function, MAX() function and MIN() function.
Due to space limitations, the detailed information of the pdf document is too comprehensive, and there are too many details, so only some of the knowledge points are screenshots for a rough introduction, and each small node has more detailed content! There will not only be an outline and a list, the program ape (yuan) in need can help Sanlian, backstage private message [data] or directly add the assistant WeChat mxj94670 to get
Chapter 13 Group Statistics
This chapter introduces how to use the GROUP BY clause to group data for statistics in order to summarize the contents of the data table. And introduced the use of WHERE clause or HAVING clause to filter grouping results.
Chapter 14 Simple Subqueries
Subqueries can complete more complex situations in SQL queries. This chapter mainly introduces some simple uses of subqueries.
Chapter 15 Multi-line Subqueries
Multi-row subqueries are implemented through multi-row comparison operators, and the return value is multiple rows. Commonly used multi-line comparison operators include: IN and NOT IN, ALL and ANY/SOME, EXISTS and NO EXISTS operators. This chapter mainly introduces the applications of these multi-line comparison operators.
Chapter 16 Multiple Table Connections
One of the most powerful features of SQL is the ability to connect multiple tables when querying data. In SQL query statements, connection is a very important operation. More and more complex queries can be realized through connection. This chapter will introduce multi-table joins and combined queries in SQL, which mainly include inner joins, outer joins, self-joins, and combined queries. Through the study of this chapter, readers will have a deeper understanding of more complex data queries.
Chapter 17 Inserting Data
SELECT is the most commonly used SQL statement. In addition, there are three other commonly used SQL statements, namely INSER' insert statement, UPDATE update statement and DELETE delete statement. This chapter will introduce the INSERT statement in SQL.
Chapter 18 Updating and Deleting Data
Sometimes you need to update a row of data in the data table, or delete some data, then you need to use the UPDATE and DELETE statements in SQL. This chapter will introduce the UPDATE and DELETE statements in SQL.
Chapter 19 Using Views
A view is a commonly used database object, which stores the result of a query in the data in the form of a virtual table. The view does not exist in the database as a stored data set. The structure and content of the view is based on the query of the table, and includes rows and columns like the table. The row and column data is derived from the table it refers to and is dynamically generated during the process of referencing the view. Through the study of this chapter, readers will have a certain understanding of the creation of views, as well as querying, modifying and deleting data through views.
Chapter 20 Using Stored Procedures
Stored procedures can change the operating performance of SQL statements and improve execution efficiency; they can also be used as a security mechanism to allow users to access unauthorized tables or views through it. This chapter will mainly introduce the creation, execution, viewing, modification and deletion of stored procedures, and operations on stored procedures containing parameters.
Chapter 21 Using Cursors
The cursor provides a flexible means of retrieving data from the table and performing operations. Cursors are mainly used on the server to process SQL statements sent from the client to the server, or data processing requests in batches, stored procedures, and triggers. The point of a cursor is that it can locate a row in the result set and perform specific operations on the row of data, which provides great convenience for processing data.
Chapter 22 Transaction Processing
The data in the database may change at all times, but this change must be within a reasonable range, that is, the data must be consistent. Transaction is an important means to ensure data consistency. This chapter will focus on explaining the concept of transaction.
Chapter 23 Database Management
Although the manual creation and maintenance of the SQL Server database is simple and easy to learn and easy to manage, it cannot save the work process. Each operation needs to be repeated, and it is not easy to use when the amount of operation is large. So in many cases, you need to use statements to create, modify, and delete databases.
Chapter 24 Data Table Management
The most important thing in relational databases is the table. It stores, displays and organizes all data information in the database in the form of a two-dimensional table composed of rows and columns. This chapter introduces in detail how to manage data tables from four aspects: creating data tables, viewing data tables, modifying data tables and deleting data tables.
Appendix 1 Common SQL commands
This book suits as the study book of SQL abecedarian, suits as the reference reference book that program development personnel and database management personnel consult at any time.
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