dot-has_column: Check if a column exists in a table (S3 generic)

In framework: Structured Data Science Project Scaffolding

Check if a column exists in a table (S3 generic)

Description

Cross-database method to check if a column exists in a table. Uses database-specific introspection methods via S3 dispatch.

Usage

.has_column(conn, table_name, column_name)

## S3 method for class 'SQLiteConnection'
.has_column(conn, table_name, column_name)

## S3 method for class 'PqConnection'
.has_column(conn, table_name, column_name)

## S3 method for class 'MariaDBConnection'
.has_column(conn, table_name, column_name)

## S3 method for class ''Microsoft SQL Server''
.has_column(conn, table_name, column_name)

## S3 method for class 'duckdb_connection'
.has_column(conn, table_name, column_name)

## Default S3 method:
.has_column(conn, table_name, column_name)

Arguments

conn	Database connection (DBIConnection)
table_name	Character. Name of the table
column_name	Character. Name of the column to check

Value

Logical. TRUE if column exists, FALSE otherwise

Functions

• .has_column(SQLiteConnection): SQLite implementation using PRAGMA

• .has_column(PqConnection): PostgreSQL implementation using information_schema

• .has_column(MariaDBConnection): MySQL/MariaDB implementation using information_schema

• .has_column(`Microsoft SQL Server`): SQL Server implementation using information_schema

• .has_column(duckdb_connection): DuckDB implementation using information_schema

• .has_column(default): Default implementation for unknown database types

Examples

if (FALSE) {
conn <- connection_get("my_db")
has_deleted_at <- .has_column(conn, "users", "deleted_at")
DBI::dbDisconnect(conn)
}

framework documentation built on Feb. 18, 2026, 1:07 a.m.