;; Exported functions for dealing with SQL syntax
(defun sql (&rest args)
- "Returns an SQL string generated from the SQL expressions
-ARGS. The expressions are translated into SQL strings and then
-concatenated with a single space delimiting each expression."
+ "Returns an SQL string generated from the expressions ARGS. The
+expressions are translated into SQL strings and then concatenated
+with a single space delimiting each expression. An error of type
+SQL-USER-ERROR is signalled if any element in ARGS is not of the
+supported types (a symbol, string, number or symbolic SQL
+expression) or a list or vector containing only these supported
+types."
(format nil "~{~A~^ ~}" (mapcar #'sql-output args)))
(defun sql-expression (&key string table alias attribute type)
- "Returns an SQL expression constructed from the supplied arguments
-which may be combined as follows: ATTRIBUTE and TYPE; ATTRIBUTE;
-ALIAS or TABLE and ATTRIBUTE and TYPE; ALIAS or TABLE and
-ATTRIBUTE; TABLE, ATTRIBUTE and TYPE; TABLE and ATTRIBUTE; TABLE
-and ALIAS; TABLE; and STRING."
+ "Returns an SQL expression constructed from the supplied
+arguments which may be combined as follows: ATTRIBUTE and TYPE;
+ATTRIBUTE; ALIAS or TABLE and ATTRIBUTE and TYPE; ALIAS or TABLE
+and ATTRIBUTE; TABLE, ATTRIBUTE and TYPE; TABLE and ATTRIBUTE;
+TABLE and ALIAS; TABLE; and STRING. An error of type
+SQL-USER-ERROR is signalled if an unsupported combination of
+keyword arguments is specified."
(cond
(string
(make-instance 'sql :string string))
(make-instance 'sql-ident-table :name table
:table-alias alias))))
-(defun sql-operator (operation)
- "Returns the Lisp symbol corresponding to the SQL operation
- represented by the symbol OPERATION."
- (typecase operation
+(defun sql-operator (operator)
+ "Returns the Lisp symbol corresponding to the SQL operator
+ represented by the symbol OPERATOR. If OPERATOR does not
+ represent a supported SQL operator or is not a symbol, nil is
+ returned."
+ (typecase operator
(string nil)
- (symbol (gethash (symbol-name-default-case (symbol-name operation))
- *sql-op-table*))))
-
-(defun sql-operation (operation &rest rest)
- "Returns an SQL expression constructed from the supplied SQL
-operator or function OPERATION and its arguments REST. If
-OPERATION is passed the symbol FUNCTION then the first value in
-REST is taken to be a valid SQL function and the remaining values
-in REST its arguments."
- (if (sql-operator operation)
- (apply (symbol-function (sql-operator operation)) rest)
- (error "~A is not a recognized SQL operator." operation)))
+ (symbol (values (gethash (symbol-name-default-case (symbol-name operator))
+ *sql-op-table*)))))
+
+(defun sql-operation (operator &rest args)
+ "Returns an SQL expression constructed from the supplied symbol
+OPERATOR representing an SQL operator or function and its
+arguments ARGS. An error of type SQL-USER-ERROR is signalled if
+OPERATOR is not a symbol representing a supported SQL
+operator. If OPERATOR is passed the symbol FUNCTION then the
+first value in ARGS must be a string representing a valid SQL
+function and the remaining values in ARGS its arguments as
+strings."
+ (if (sql-operator operator)
+ (apply (symbol-function (sql-operator operator)) args)
+ (error 'sql-user-error
+ :message
+ (format nil "~A is not a recognized SQL operator." operator))))