Skip to main content

sql.symbolAlias(symbol1, symbol2)

ADVANCED - most users will not need this function.

Creates a "blank" SQL fragment to include into a query to inform pg-sql2 to treat symbol2 as if it were the same as symbol1 when generating SQL identifiers. Useful in deduplication when you find out two symbols are equivalent.

Syntax​

sql.symbolAlias(symbol1: symbol, symbol2: symbol): SQL

Parameters​

  • symbol1 - The primary symbol
  • symbol2 - The symbol that should be treated as equivalent to symbol1

Return value​

Returns a SQL fragment that establishes the symbol alias relationship. This fragment needs to be included in the final query to take effect, typically at the beginning of the query.

Example​

import { sql } from "pg-sql2";

const userTable = Symbol("users");
const u = Symbol("u"); // Alias for shorter reference

const aliasDeclaration = sql.symbolAlias(userTable, u);

const query = sql`
  ${aliasDeclaration}
  SELECT ${sql.identifier(u, "name")}, ${sql.identifier(userTable, "email")}
  FROM users AS ${sql.identifier(u)}
`;

// Both userTable and u will resolve to the same identifier

Notes​

  • Symbol aliases must be declared before the symbols are used in the query
  • Each symbol can have multiple aliases pointing to it
  • Aliases are resolved during SQL compilation