LET (Snowflake Scripting)

Assigns an expression to a Snowflake Scripting variable, cursor, or RESULTSET.

For more information on variables, cursors, and RESULTSETs, see:

Note

This Snowflake Scripting construct is valid only within a Snowflake Scripting block.

See also:

DECLARE

Syntax

LET { <variable_assignment> | <cursor_assignment> | <resultset_assignment> }

The syntax for each type of assignment is described below in more detail.

Variable assignment syntax

Use the following syntax to assign an expression to a variable.

LET <variable_name> <type> { DEFAULT | := } <expression> ;

LET <variable_name> { DEFAULT | := } <expression> ;

Where:

variable_name

The name of the variable. The name must follow the naming rules for object identifiers.

type

A SQL data type.

DEFAULT expression or . := expression

Assigns the value of expression to the variable.

If both type and expression are specified, the expression must evaluate to a data type that matches.

For example, the following LET statements declare three variables of type NUMBER, with precision set to 38 and scale set to 2. All three variables have a default value, using either DEFAULT or := to specify it.

BEGIN
  ...
  LET profit NUMBER(38, 2) DEFAULT 0.0;
  LET revenue NUMBER(38, 2) DEFAULT 110.0;
  LET cost NUMBER(38, 2) := 100.0;
  ...

For more examples, see:

Cursor assignment syntax

Use one of the following syntaxes to assign an expression to a cursor.

LET <cursor_name> CURSOR FOR <query> ;

LET <cursor_name> CURSOR FOR <resultset_name> ;

Where:

cursor_name

The name to give the cursor. This can be any valid Snowflake identifier that is not already in use in this block. The identifier is used by other cursor-related commands, such as FETCH (Snowflake Scripting).

query

The query that defines the result set that the cursor iterates over.

This can be almost any valid SELECT statement.

resultset_name

The name of the RESULTSET for the cursor to operate on.

For example, the following LET statement declares cursor c1 for a query:

BEGIN
  ...
  LET c1 CURSOR FOR SELECT price FROM invoices;
  ...

For more examples, see Working with cursors.

RESULTSET assignment syntax

Use the following syntax to assign an expression to a RESULTSET.

<resultset_name> := ( <query> ) ;

Where:

resultset_name

The name to give the RESULTSET.

The name should be unique within the current scope.

The name must follow the naming rules for Object identifiers.

DEFAULT query or . := query

Assigns the value of query to the RESULTSET.

For example, the following LET statement declares RESULTSET res for a query:

BEGIN
  ...
  LET res RESULTSET := (SELECT price FROM invoices);
  ...

For more examples, see Working with RESULTSETs.