Overview of the Structure of eSQL Statements

• Literals
• FROM Clause
• SELECT Clause
• WHERE Clause
• Functions
• References
• UNION and EXCEPT
• ORDER BY Clause
• TOP Clause
• Addressing Columns Using Their Number

The structure of statements in eSQL hardly differs from SQL. An eSQL statement consists of three parts, the SELECT clause, the FROM clause, and the WHERE clause. The SELECT clause is mandatory; both other clauses are optional. However, omitting the FROM clause is only rarely sensible. Thus

Select 1

is a valid statement.

All three clauses can become very complex and also contain other statements as subselects. The clauses are covered in more detail in separate sections.

Several statements can be linked with the keyword UNION and EXCEPT as in SQL.