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Moderne licensed

Find COUNT subqueries used as existence checks

Recipe IDorg.openrewrite.sql.antipattern.FindCountAsExistenceCheck
Artifactorg.openrewrite.recipe:rewrite-sql

A scalar COUNT subquery compared to 0 or 1 tallies every matching row even though the outcome is decided by the first one. EXISTS or NOT EXISTS lets the engine stop as soon as a match is found. Comparisons against other values, such as > 5, express a genuine cardinality requirement and are not flagged.

Single recipeProprietary

Usage

This recipe has no required configuration options. You’ll need the Moderne CLI configured before running the command below.

mod run . --recipe org.openrewrite.sql.antipattern.FindCountAsExistenceCheck

If the recipe isn’t available locally, install it with:

mod config recipes jar install org.openrewrite.recipe:rewrite-sql:2.14.1

Data tables

Structured output this recipe can produce.

  • SQL anti-patternsSQL statements matching performance anti-pattern rules.org.openrewrite.sql.table.SqlAntiPatterns
  • Source files that had resultsSource files that were modified by the recipe run.org.openrewrite.table.SourcesFileResults
  • Source files that had search resultsSearch results that were found during the recipe run.org.openrewrite.table.SearchResults
  • Source files that errored on a recipeThe details of all errors produced by a recipe run.org.openrewrite.table.SourcesFileErrors
  • Recipe performanceStatistics used in analyzing the performance of recipes.org.openrewrite.table.RecipeRunStats