fix runFirstColumn for neo4j-graphql-js, fixes #819 fixes #776

docs/overview.adoc

@@ -554,7 +554,8 @@ CALL apoc.generate.simple([2,2,2,2], null, null)
 [cols="1m,5"]
 |===
 | CALL apoc.cypher.run(fragment, params) yield value | executes reading fragment with the given parameters
-| apoc.cypher.runFirstColumn(statement, params, [expectMultiplevalues]) | function that executes statement with given parameters returning first column only, if expectMultipleValues is true will collect results into a list
+| apoc.cypher.runFirstColumnSingle(statement, params) | function that executes statement with given parameters returning first column only, will return first/single row or null
+| apoc.cypher.runFirstColumnMany(statement, params) | function that executes statement with given parameters returning first column only, will collect all rows into a list
 | CALL apoc.cypher.runFile(file or url,{config}) yield row, result | runs each statement in the file, all semicolon separated - currently no schema operations
 | CALL apoc.cypher.runFiles([files or urls],{config}) yield row, result | runs each statement in the files, all semicolon separated
 | CALL apoc.cypher.runSchemaFile(file or url,{config}) - allows only schema operations, runs each schema statement in the file, all semicolon separated

src/main/java/apoc/cypher/CypherFunctions.java

@@ -9,7 +9,9 @@
 import org.neo4j.procedure.UserFunction;
 
 import java.util.Collections;
+import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import static apoc.cypher.Cypher.withParamMapping;
 
@@ -21,16 +23,30 @@ public class CypherFunctions {
     public GraphDatabaseService db;
 
     @UserFunction
-    @Description("apoc.cypher.runFirstColumn(kernelTransaction, params, expectMultipleValues) - executes kernelTransaction with given parameters, returns first column only, if expectMultipleValues is true will collect results into an array")
+    @Deprecated
+    @Description("use either apoc.cypher.runFirstColumnMany for a list return or apoc.cypher.runFirstColumnSingle for returning the first row of the first column")
     public Object runFirstColumn(@Name("cypher") String statement, @Name("params") Map<String, Object> params, @Name(value = "expectMultipleValues",defaultValue = "true") boolean expectMultipleValues) {
         if (params == null) params = Collections.emptyMap();
-        try (Result result = db.execute(withParamMapping(statement, params.keySet()), params)) {
+        String resolvedStatement = withParamMapping(statement, params.keySet());
+        if (!resolvedStatement.contains(" runtime")) resolvedStatement = "cypher runtime=slotted " + resolvedStatement;
+        try (Result result = db.execute(resolvedStatement, params)) {
 
         String firstColumn = result.columns().get(0);
         try (ResourceIterator<Object> iter = result.columnAs(firstColumn)) {
-            if (expectMultipleValues) return iter.stream().toArray();
+            if (expectMultipleValues) return iter.stream().collect(Collectors.toList());
             return iter.hasNext() ? iter.next() : null;
         }
       }
     }
+
+    @UserFunction
+    @Description("apoc.cypher.runFirstColumnMany(statement, params, expectMultipleValues) - executes statement with given parameters, returns first column only collected into a list, params are available as identifiers")
+    public List<Object> runFirstColumnMany(@Name("cypher") String statement, @Name("params") Map<String, Object> params) {
+        return (List)runFirstColumn(statement, params, true);
+    }
+    @UserFunction
+    @Description("apoc.cypher.runFirstColumnSingle(statement, params, expectMultipleValues) - executes statement with given parameters, returns first element of the first column only, params are available as identifiers")
+    public Object runFirstColumnSingle(@Name("cypher") String statement, @Name("params") Map<String, Object> params) {
+        return runFirstColumn(statement, params, false);
+    }
 }

src/test/java/apoc/cypher/CypherTest.java

@@ -86,11 +86,17 @@ public void testRunVariable() throws Exception {
     }
 
     @Test
-    public void testRunFirstColumn() throws Exception {
-        testCall(db, "RETURN apoc.cypher.runFirstColumn('RETURN a + 7 AS b', {a: 3}, false) AS s",
+    public void testRunFirstColumnSingle() throws Exception {
+        testCall(db, "RETURN apoc.cypher.runFirstColumnSingle('RETURN a + 7 AS b', {a: 3}) AS s",
                 r -> assertEquals(10L, (r.get("s"))));
     }
 
+    @Test
+    public void testRunFirstColumnMany() throws Exception {
+        testCall(db, "RETURN apoc.cypher.runFirstColumnMany('UNWIND range(1,a) as id RETURN id', {a: 3}) AS s",
+                r -> assertEquals(Arrays.asList(1L,2L,3L), (r.get("s"))));
+    }
+
     @Test
     public void testRunFirstColumnBugCompiled() throws Exception {
         ResourceIterator<Node> it = db.execute("CREATE (m:Movie  {title:'MovieA'})<-[:ACTED_IN]-(p:Person {name:'PersonA'})-[:ACTED_IN]->(m2:Movie {title:'MovieB'}) RETURN m").columnAs("m");