@balena/abstract-sql-compiler - npm Package Compare versions

Comparing version 7.6.0 to 7.7.0-empty-query-optimization-39431de07eeb98d731a114c1717575d364ddc06f

CHANGELOG.md

@@ -7,2 +7,6 @@ # Change Log
 
+## 7.7.0 - 2021-01-01
+
+* Optimize EXISTS/NOT EXISTS for empty queries [Pagan Gazzard]
+
 ## 7.6.0 - 2021-01-01
@@ -9,0 +13,0 @@

out/AbstractSQLOptimiser.js

@@ -29,2 +29,19 @@ "use strict";
 };
+const isEmptySelectQuery = (query) => {
+    const [type, ...rest] = query;
+    switch (type) {
+        case 'SelectQuery':
+            for (const arg of rest) {
+                if (arg[0] === 'Where') {
+                    const maybeBool = arg[1];
+                    if (maybeBool[0] === 'Boolean') {
+                        if (maybeBool[1] === false) {
+                            return true;
+                        }
+                    }
+                }
+            }
+    }
+    return false;
+};
 const rewriteMatch = (name, matchers, rewriteFn) => (args) => {
@@ -793,5 +810,12 @@ checkArgs(name, args, matchers.length);
     },
-    Exists: (args) => {
+    Exists: tryMatches(Helper((args) => {
         checkArgs('Exists', args, 1);
         const arg = getAbstractSqlQuery(args, 0);
+        if (isEmptySelectQuery(arg)) {
+            return ['Boolean', false];
+        }
+        return false;
+    }), (args) => {
+        checkArgs('Exists', args, 1);
+        const arg = getAbstractSqlQuery(args, 0);
         const [type, ...rest] = arg;
@@ -805,4 +829,11 @@ switch (type) {
         }
-    },
-    NotExists: (args) => {
+    }),
+    NotExists: tryMatches(Helper((args) => {
+        checkArgs('Exists', args, 1);
+        const arg = getAbstractSqlQuery(args, 0);
+        if (isEmptySelectQuery(arg)) {
+            return ['Boolean', true];
+        }
+        return false;
+    }), (args) => {
         checkArgs('NotExists', args, 1);
@@ -818,3 +849,3 @@ const arg = getAbstractSqlQuery(args, 0);
         }
-    },
+    }),
     Not: tryMatches(Helper((args) => {
@@ -821,0 +852,0 @@ checkArgs('Not', args, 1);

package.json

 {
   "name": "@balena/abstract-sql-compiler",
-  "version": "7.6.0",
+  "version": "7.7.0-empty-query-optimization-39431de07eeb98d731a114c1717575d364ddc06f",
   "description": "A translator for abstract sql into sql.",
@@ -5,0 +5,0 @@ "main": "out/AbstractSQLCompiler.js",

src/AbstractSQLOptimiser.ts

@@ -49,2 +49,20 @@ import * as _ from 'lodash';
 
+const isEmptySelectQuery = (query: AbstractSqlQuery): boolean => {
+	const [type, ...rest] = query;
+	switch (type) {
+		case 'SelectQuery':
+			for (const arg of rest) {
+				if (arg[0] === 'Where') {
+					const maybeBool = arg[1];
+					if (maybeBool[0] === 'Boolean') {
+						if (maybeBool[1] === false) {
+							return true;
+						}
+					}
+				}
+			}
+	}
+	return false;
+};
+
 const rewriteMatch = (
@@ -918,26 +936,46 @@ name: string,
 	},
-	Exists: (args) => {
-		checkArgs('Exists', args, 1);
-		const arg = getAbstractSqlQuery(args, 0);
-		const [type, ...rest] = arg;
-		switch (type) {
-			case 'SelectQuery':
-			case 'UnionQuery':
-				return ['Exists', typeRules[type](rest)];
-			default:
-				return ['Exists', AnyValue(arg)];
-		}
-	},
-	NotExists: (args) => {
-		checkArgs('NotExists', args, 1);
-		const arg = getAbstractSqlQuery(args, 0);
-		const [type, ...rest] = arg;
-		switch (type) {
-			case 'SelectQuery':
-			case 'UnionQuery':
-				return ['NotExists', typeRules[type](rest)];
-			default:
-				return ['NotExists', AnyValue(arg)];
-		}
-	},
+	Exists: tryMatches(
+		Helper<OptimisationMatchFn>((args) => {
+			checkArgs('Exists', args, 1);
+			const arg = getAbstractSqlQuery(args, 0);
+			if (isEmptySelectQuery(arg)) {
+				return ['Boolean', false] as AbstractSqlQuery;
+			}
+			return false;
+		}),
+		(args) => {
+			checkArgs('Exists', args, 1);
+			const arg = getAbstractSqlQuery(args, 0);
+			const [type, ...rest] = arg;
+			switch (type) {
+				case 'SelectQuery':
+				case 'UnionQuery':
+					return ['Exists', typeRules[type](rest)];
+				default:
+					return ['Exists', AnyValue(arg)];
+			}
+		},
+	),
+	NotExists: tryMatches(
+		Helper<OptimisationMatchFn>((args) => {
+			checkArgs('Exists', args, 1);
+			const arg = getAbstractSqlQuery(args, 0);
+			if (isEmptySelectQuery(arg)) {
+				return ['Boolean', true] as AbstractSqlQuery;
+			}
+			return false;
+		}),
+		(args) => {
+			checkArgs('NotExists', args, 1);
+			const arg = getAbstractSqlQuery(args, 0);
+			const [type, ...rest] = arg;
+			switch (type) {
+				case 'SelectQuery':
+				case 'UnionQuery':
+					return ['NotExists', typeRules[type](rest)];
+				default:
+					return ['NotExists', AnyValue(arg)];
+			}
+		},
+	),
 	Not: tryMatches(
@@ -944,0 +982,0 @@ Helper<OptimisationMatchFn>((args) => {

New alerts

No v1

Quality

Package is not semver >=1. This means it is not stable and does not support ^ ranges.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

573865

increased by0.81%

Number of package files

52

increased by1.96%

Lines of code

12640

increased by1.05%

Worsened metrics

Number of low quality alerts

2

increased by100%

No dependency changes