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Create a macro in DuckLake

Source: R/discovery.R
db_create_macro.Rd

Creates a SQL macro stored in the DuckLake catalog. Macros are reusable SQL expressions that can be scalar (return a single value) or table-valued (return a table). Macros support time travel.

Usage

db_create_macro(
  schema = "main",
  name,
  params = character(0),
  body,
  table_macro = FALSE,
  replace = FALSE
)

Arguments

schema

Schema name (default "main")

name

Macro name

params

Character vector of parameter names, or named character vector with types (e.g., c(a = "INTEGER", b = "VARCHAR"))

body

SQL expression for the macro body

table_macro

If TRUE, create a table macro (returns a table). Default FALSE.

replace

If TRUE, replace existing macro (default FALSE)

Value

Invisibly returns the qualified macro name

See also

db_list_macros(), db_drop_macro()

Examples

if (FALSE) { # \dontrun{
db_connect(...)

# Scalar macro
db_create_macro(name = "add_values",
                params = c("a", "b"),
                body = "a + b")

# Table macro
db_create_macro(name = "filtered_sales",
                params = c(min_value = "INTEGER"),
                body = "SELECT * FROM sales WHERE value > min_value",
                table_macro = TRUE)

# Use the macros
db_query("SELECT add_values(10, 20)")
db_query("SELECT * FROM filtered_sales(100)")
} # }