对于PostgreSQL: sql \dt 或者 sql SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'; 对于SQL Server: sql SELECT TABLE_NAME FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE = 'BASE TABLE' AND TABLE_CATALOG='your_database_name'; 请将your_database_name替换为你的...
A single PostgreSQL server can contain many databases. Let’s explore three different approaches to list databases in PostgreSQL!
REFERENCES: value must exist in a column in another table After the columns are defined, table-wide constraints may be declared. Table-wide constraints can be either UNIQUE, PRIMARY KEY, CHECK, or REFERENCES. How to Create a Table in PostgreSQL Let's create a test table to pract...
Basic SELECT Query to Retrieve Tables Inside INFORMATION_SCHEMA in PostgreSQLA very simple query to get all the tables inside this SCHEMA would be to write something like this.select * from information_schema.tables This would return a table like this.Output:...
tablespace_name:Specify the name of the tablespace. If you do not specify the tablespace, the table will be created inpg_defaulttablespace PostgreSQL supports the following column constraints: PRIMARY KEY:The primary key identifies a record from the table uniquely. A PostgreSQL table can have only...
The table will be created. To get objects of the “tablespace” tablespace, execute the following query: SELECTts.spcname, cl.relnameFROMpg_class clJOINpg_tablespace tsONcl.reltablespace = ts.oidWHEREts.spcname ='tablespace'; This query will return all the objects in the tablespace. The out...
TheINSERT INTOstatement is the key to adding records to a table in PostgreSQL. Syntax and Usage The basic syntax is: INSERTINTOtable_name(column1,column2,column3,...) VALUES(value1,value2,value3,...); Simple Insertion Example Inserting a user into our previously created users table: ...
Step 4: Describe the Altered/Modified Table Let’s execute the“\d”command to verify that the targeted table has been altered successfully: \dteam_details; The above snippet verifies the working of the“ALTER TABLE”command. How to Drop a Column in PostgreSQL?
As expected, this works as well! Hence, we can create either a table or a view in PostgreSQL, which works just like thedualtable in Oracle. Let us look at other examples of selecting pseudo columns using adualtable in PostgreSQL to see if it works in all cases. ...
Let’s set up a new table in PostgreSQL and use it to look at a few helpful ways that DISTINCT can remove duplicates and reveal useful information from the data. First, connect to psql terminal: /usr/pgsql-11/bin/psql -U postgres postgres ...