What are DBMS languages

Database languages

DDL (Data Definition Language)

If you want to describe data and data structures, you need a suitable description tool, a Data description language. This is used to define and change the data scheme.
Typical DDL operations (with the corresponding keywords in the relational database language SQL) are:

  • Creation of tables and definition of attributes ("create table ...")
  • Changing tables by adding or removing attributes ("alter table ...")
  • Deleting entire tables including their content (!) ("Drop table ...")

DML (Data Manipulation Language)

In addition, a language is required to describe the work options with data (save, search, read, change), the so-called data manipulation. Such operations can be performed with aData manipulation language be performed. The keywords mentioned typically appear in such languages, mostly in English ("insert, modification, update, delete, select").
Typical DML operations (with the corresponding keywords in the relational database language SQL) are:

  • Inserting data ("insert")
  • Changing entries ("update")
  • Deleting entries ("delete")
  • Data queries ("select")



Often, however, these two languages ​​for defining and manipulating databases are combined in one comprehensive language. A good example is the relational query language SQL (Structured Query Language), which is covered in more detail in the lesson "Relational query language SQL".