Merge pull request 'exists' (#13) from dev into main

Reviewed-on: #13

package.json

@@ -1,6 +1,6 @@
 {
   "name": "dblang",
-  "version": "1.0.0",
+  "version": "0.6.2",
   "description": "",
   "main": "dist/db.js",
   "types": "dist/db.d.ts",

readme.md

@@ -238,6 +238,7 @@ BooleanModifier:
 - `le(v1, v2, ...)`
 - `not(v1)`
 - `like(v1, v2)`
+- `exists(s)`
 
 NumberModifier:
 - `plus(v1, v2, ...)`
@@ -248,7 +249,7 @@ NumberModifier:
 StringModifier:
 - `concat(v1, v2, ...)`
 
-(v\* = string, number, boolean, null, Modifier, Aggregation, select Query, Attribute)
+(v\* = string, number, boolean, null, Modifier, Aggregation, select Query, Attribute; s = selectQuery)
 
 #### Joins
 

src/defaultHandler.ts

@@ -751,6 +751,22 @@ export class Handler {
             }
             return builder;
         },
+        exists: (handler: Handler, a: allModifierInput[]):QueryBuilder =>{
+            let e = a[0];
+            if (e instanceof Attribute || e instanceof AttributeAlias) return new QueryBuilder([{ data: "exists (" + e.getString(handler) + ")" }])
+            if (e instanceof Modifier || e instanceof selectQuery || e instanceof Aggregation) {
+                const builder = new QueryBuilder();
+                builder.addCode("exists (");
+                builder.append(e.serialize(handler));
+                builder.addCode(")");
+                return builder;
+            }
+            return new QueryBuilder([
+                { data: "exists (" },
+                { inject: true, data: e },
+                { data: ")" }
+            ]);
+        },
         concat: (handler: Handler, a: allModifierInput[]): QueryBuilder => {
             const builder = new QueryBuilder();
             builder.addCode("CONCAT(");

src/funcs.ts

@@ -20,6 +20,8 @@ export const not = (arg: allModifierInput) => new BooleanModifier("not", [arg]);
 export const like = (a: allModifierInput, b: allModifierInput) => new BooleanModifier("like", [a, b]);
 export const regexp = (a: allModifierInput, b: allModifierInput) => new BooleanModifier("regexp", [a, b]);
 
+export const exists = (q: selectQuery) => new BooleanModifier("exists", [q]);
+
 export const concat = (...args: allModifierInput[]) => new StringModifier("concat", args);
 
 //aggregations