When using relational database management systems (RDBMSs) we often hear terms like DDL, DML, DQL, DCL, and TCL. But what exactly are they?
In this article we’ll look at what TCL stands for in the context of SQL, and what it does.
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How SERIAL Works in PostgreSQL
In PostgreSQL we can create auto-incrementing columns using the serial data type. The serial type causes the column to be automatically populated with an auto-incrementing value each time a new row is inserted. The same applies for the smallserial and bigserial types.
This article provides an overview of how these data types work.
What is DCL?
When using relational database management systems (RDBMSs) we often hear terms like DDL, DML, DQL, TCL, and DCL. But what exactly are they?
In this article we’ll look at what DCL stands for in the context of SQL, and what it does.
What is DQL?
We often hear terms like DDL, DML, DQL, TCL, and DCL when using relational database management systems (RDBMSs). But what exactly are they?
In this article we’ll look at what DQL stands for, and what it does.
What is DML?
We often hear terms like DDL, DML, DQL, and DCL when using relational database management systems (RDBMSs). But what exactly are they?
In this article we’ll look at what DML stands for, and what it does.
What is DDL?
We often encounter terms like DDL, DML, DQL, DCL, and TCL when using relational database management systems (RDBMSs). But what do they mean?
In this article we’ll look at what DDL stands for and what it does.
How CONVERT() Works in MySQL
In MySQL, CONVERT() is a built in function that converts a value to another data type. It takes a value of one type and returns a value of the specified type.
We provide the value as an argument when we call the function, as well as the type that we want it converted to.
The CONVERT() function is similar to the CAST() function, which also converts between data types.
MySQL ROW_COUNT() Explained
In MySQL, ROW_COUNT() is a built-in function that returns the number of rows updated, inserted, or deleted by the preceding statement.
The value returned by ROW_COUNT() is often the same as the row count that the mysql client displays following statement execution, as well as the value from the mysql_affected_rows() C API function.
SQLite CHANGES() Function
The SQLite changes() function returns the number of database rows that were changed, inserted or deleted by the most recently completed INSERT, DELETE, or UPDATE statement, exclusive of statements in lower-level triggers.
Basically, it allows us to see how many rows are affected when we run any of those statements.