Example: Drop a Column from All Objects Copy CREATE OR REPLACE VIEW employee_dtl AS SELECT * FROM employee;Now, if you try to remove the email column of the employee table, then PostgreSQL will raise an error, as shown below.To remove a column which is being used in other DB objects,...
After the column list, specify a constraint for the table, which we can term a table-level constraint. It defines rules for the data in the table. INHERITS clause:Specify an existing table name from which the new table is getting inherited. This defines the newly created table will have c...
@Insert("<script>INSERT INTO ${extInfo.tableName}\n" + " (id,requestid,code,columnname,datatype) " + " <foreach collection=\"extInfo.list\" item=\"item\" separator=\"UNION ALL\">\n" + " select #{item.id}, #{item.requestId}, #{item.code}, #{item.columnName},#{item.data...
In this tutorial, we’ll explore various approaches to remove the last two characters from a string column in MySQL, PostgreSQL, and SQL Server using the Baeldung University database schema. 2. Problem Statement We focus on the Departments table which contains the name and code of each departme...
To remove the column we just created, enter this command: ALTER TABLE pg_equipment DROP COLUMN working_order; We can rename the entire table with this command: ALTER TABLE pg_equipment RENAME TO playground_equip; Deleting Tables in PostgreSQL ...
We can use the DELETE statement with the condition based on theStockcolumn value 0: -- Delete all the out of stock (Where Stock is 0) books (rows) from the table Book DELETE FROM dbo.Book WHERE Stock=0 View the data after the deletion ...
Example 4: How to Use ARRAY_REMOVE() Function on Table’s Data? We have created a table named “st_information” that contains the following data: SELECT * FROM st_information; Suppose we want to remove “joe” from the st_name column. For that purpose, we will use the ARRAY_REMOVE(...
VACUUMcan only remove those row versions (also known as “tuples”) that are not needed any more. A tuple is not needed if the transaction ID of the deleting transaction (as stored in thexmaxsystem column) is older than the oldest transaction still active in the PostgreSQL database (or ...
SELECTREPLACE('PostgreSQL','e','')ASmodified_string; Output: Example 2: Removing a Specific Character from a Column – REPLACE() We will be usingsummerfruitstable. Removing a particular character from string in PostgreSQL is accomplished by using REPLACE() function as shown below ...
Not: MySQL, SQL Server, PostgreSQL The next method we’ll look at is using a subquery to identify and delete duplicate data. I’ll show you the query first, then explain how it works. DELETEFROMtablenameaWHEREa.rowid>ANY(SELECTb.rowidFROMtablenamebWHEREa.column1=b.column1); ...