Summarise how a table is used across all scripts

Given the full relationships data.frame returned by sq_sql_mine, finds every script that references a given table and describes the role the table plays in each relationship.

Usage

sq_table_usage(relationships, table_name)

Arguments

relationships: A data.frame as returned by sq_sql_mine.
table_name: The table name to look up (a single string, matched case-insensitively against both source_table and target_table).

Value

A data.frame with columns:

script_name: The script that references the table.
role: "source" when the table appears in a FROM clause, "join_target" when it is the target of a JOIN, or "insert_target" when it is the destination of an INSERT.

One row per unique script_name / role combination. Returns a zero-row data.frame (with the correct columns) if the table is not found.

Examples

if (FALSE) { # \dontrun{
scripts <- sq_read_sql_files("path/to/sql")
relationships <- sq_sql_mine(scripts)
sq_table_usage(relationships, "dbo.patients")
} # }