- ISO/IEC 9075 defines Structured Query Language (SQL). The scope of SQL is the definition of data structure and the operations on data stored in that structure. ISO/IEC 9075-1, ISO/IEC 9075-2 and ISO/IEC 9075-11 encompass the minimum requirements of the language. Other parts define extensions. ISO/IEC 9075-4 2011 specifies the syntax and semantics of statements to add a procedural capability to the SQL language in functions and procedures. It includes statements to direct the flow of control, define variables, make assignments and handle exception conditions.