Statement Expressions

The library provides classes to represent SQL statements as expressions.

The following expression classes are available:

• CaseX

CaseX

The CaseX expression allows you to create SQL CASE statements.

The CaseX class accepts the following arguments:

• value comparison condition in the CASE expression:
  • string is treated as a table column name which will be quoted before usage in the SQL statement;
  • array is treated as a condition to check, see QueryInterface::where();
  • other values will be converted to their string representation using QueryBuilderInterface::buildValue(). If not provided, the CASE expression will be a WHEN-THEN structure without a specific case value.
• valueType optional data type of the CASE expression which can be used in some DBMS to specify the expected type;
• ...args List of WHEN-THEN conditions and their corresponding results represented as WhenThen instances or ELSE value in the CASE expression. String ELSE value will be quoted before usage in the SQL statement.

For example:

$case = new CaseX(
    'status',
    when1: new WnenThen('active', 'Active User'),
    when2: new WnenThen('inactive', 'Inactive User'),
    else: 'Unknown Status',
);

This will generate the following SQL:

CASE "status"
    WHEN 'active' THEN 'Active User'
    WHEN 'inactive' THEN 'Inactive User'
    ELSE 'Unknown Status'
END