Pgadmin4 of PostgreSQL graphical interface tool

1、 brief introduction

Open source database PostgreSQL Graphics management tools commonly used are Navicat, besides , We also have PostgreSQL It comes with itself pgAdmin4, More professional .

Navicat The interface of ：

pgAdmin4 The interface of ：

pgAdmin4 Open source database PostgreSQL Graphics management tools for , Is a desktop graphics management tool pgAdmin3 Rewriting of , follow PostgreSQL agreement It's open source. 、 free 、 Commercially available .pgAdmin4 yes python Developed web Applications , It can be deployed as web Mode is accessed through the browser , It can also be deployed to run independently in desktop mode .

download ：https://www.pgadmin.org/download/

2、Windows install

download ：https://ftp.postgresql.org/pub/pgadmin/pgadmin4/v5.1/windows/pgadmin4-5.1-x64.exe

Installation is the next step. The next step is .

in addition , If we install Windows Version of PostgreSQL database , By default, it also comes with the installation directory pgAdmin4 Tools ：

​ During installation, you can also choose ：

3、docker install pgAdmin4

If we don't want to install locally , Then you can also use the server directly docker Version of pgAdmin4.

Official website ：https://hub.docker.com/r/dpage/pgadmin4/

Detailed configuration ：https://www.pgadmin.org/docs/pgadmin4/latest/container_deployment.html

--  download docker pull dpage/pgadmin4:latest--  install docker run -p 680:80  \    -e '[email protected]' \    -e 'PGADMIN_DEFAULT_PASSWORD=lhr' \    -d dpage/pgadmin4    --  Sign in http://192.168.66.35:680

You can see , Web version of pgAdmin4 It has the same function as the desktop version .

4、 Sinicization pgAdmin4

The latest version used by Mr. Mai here ：

5、 Use pgAdmin4

5.1、 insert data

or ：

This method is also possible , But you have to determine the table before ！！

View the added data ;

5.2、 Use insert The query tool inserts multiple pieces of data

INSERT INTO STUDENT2(  ID,NAME,SUBJECTS)  VALUES (2,' Go to ','c'),(3,' open ','m'), (4,' God ','x');

View the data ：

5.3、 Use select Query data

Use the query statement to query the table

SELECT id,name FROM STUDENT2;

5.4、 Use update Update the database

Put the value in “？” The place of And finish WHERE Conditions <condition>, And then click “ perform ” Button to execute the query .

for example , hold id yes 2 Of , Change name and subjects:

The result of the query change ：

5.5、 Use delete Delete data

A statement that deletes the entire table ：

DELETE FROM public.student2;

5.6、 The question of sequencing

PostgreSQL ORDER BY Clause is used to sort data in ascending or descending order . Data is sorted on the basis of one or more columns . grammar ：SELECT column-list FROM table_name [WHERE condition] [ORDER BY column1, column2, .. columnN] [ASC | DESC];SQL Parameter description ：column_list： It specifies the column or calculation to retrieve .table_name： It specifies the table from which to retrieve records .FROM Clause must have at least one table .WHERE conditions： Optional . It stipulates that conditions must be met to retrieve records .ASC： Also optional . It sorts the result set in ascending order by expression ( Default , If no modifier is a provider ).DESC： Also optional . It sorts the result set in order by expression .

①、 Ascending sort - ORDER BY [field] ASC

Execute the following query in ascending order ORDER BY AGE Data records ：

SELECT *   FROM STUDENT2  ORDER BY NAME ASC;

according to name Sort fields in ascending order ：

②、 null - ORDER BY [field] DESC

Execute the following query in descending order ORDER BY name DESC Record of data ：

SELECT *   FROM STUDENT2 ORDER BY subjects DESC;

according to subjects Sort fields in descending order ,

③、 Multi column sorting ORDER BY

You can also use it ORDER BY Clause sorts records on multiple columns . Execute the following query from the table “student2” Press ORDER BY NAME Get records in ascending order .

5.7、 The problem of grouping

PostgreSQL GROUP BY Clause is used to group these rows together in a table with the same data . It is associated with SELECT Statement together .GROUP BY Clause collects data from multiple records , And group the results into one or more columns . It is also used to reduce redundancy in the output . grammar ：SELECT column-listFROM table_nameWHERE [conditions ]GROUP BY column1, column2....columnNORDER BY column1, column2....columnNSQL Be careful ： stay GROUP BY In the case of multiple columns , When grouping any columns you use , Make sure these columns are available in the list .

SELECT NAMEFROM STUDENT2  GROUP BY NAME;

Reduce redundant data

We can add some duplicate data in the table first , When we use GROUP BY NAME when , You can see that duplicate name data records are merged . It specifies GROUP BY Reduce redundant .

5.8、HAVING Usage of

stay PostgreSQL in ,HAVING Clause and GROUP BY Clauses are combined to use , Used to select a specific line where the result of the function satisfies certain conditions . grammar ：SELECT column1, column2 FROM table1, table2 WHERE [ conditions ] GROUP BY column1, column2 HAVING [ conditions ] ORDER BY column1, column2

①、name The field value count is greater than 1 The name of .

SELECT NAME,COUNT (NAME) FROM STUDENT2  GROUP BY NAME HAVING COUNT (NAME) > 1;

Because in the past , open , Every day is double data inserted ;

②、 The display name (name) Quantity less than 2 The record of .

SELECT NAME   FROM STUDENT2  GROUP BY NAME HAVING COUNT (NAME) < 2;