SQL helpers for scalar functions

These functions help you create custom scalar SQL translations when implementing a new backend. They are typically used within sql_translator() to define how R functions should be translated to SQL.

sql_infix() creates SQL infix operators like +, -, *, /.
sql_prefix() creates SQL prefix functions like ABS(), SQRT().
sql_cast() creates SQL cast expressions like CAST(x AS type).
sql_try_cast() creates SQL try_cast expressions (for safe casting).
sql_log() creates a SQL logarithm function with optional base.
sql_cot() creates a SQL cotangent function (as 1 / TAN(x)).
sql_runif() creates a SQL expression for generating uniform random numbers.

Usage

sql_infix(f, pad = TRUE)

sql_prefix(f, n = NULL)

sql_cast(type)

sql_try_cast(type)

sql_log()

sql_cot()

sql_runif(rand_expr, n = n(), min = 0, max = 1)

Arguments

f: The name of the SQL function as a string.
pad: If TRUE, the default, pad the infix operator with spaces.
n: For sql_prefix(), an optional number of arguments to expect. Will signal error if not correct.
type: SQL type name as a string.
rand_expr: An string giving an SQL expression that generates a random number between 0 and 1, e.g. "RANDOM()".
min, max: Range of random values.

Usage

Arguments

See also