From 59fe3c7df9cfb135547132e3bc99ddf3fddefc58 Mon Sep 17 00:00:00 2001
From: Martyn Loughran <martyn@mloughran.com>
Date: Sun, 16 Aug 2026 12:47:39 +0100
Subject: [PATCH 1/2] Fix SQL emitted for limited compound query

Previously SQL like "... = $2LIMIT $3", was emitted, resulting in an error like:

> trailing junk after parameter at or near "$2LIMIT" (PQ::PQError)
---
 spec/interro_spec.cr | 9 +++++++++
 src/query_builder.cr | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/spec/interro_spec.cr b/spec/interro_spec.cr
index 280efee..1e0d451 100644
--- a/spec/interro_spec.cr
+++ b/spec/interro_spec.cr
@@ -806,6 +806,15 @@ describe Interro do
       users.should_not contain excluded
     end
 
+    it "can limit compound queries" do
+      Array.new(2) { create_user(name: "Limit LHS") }
+      Array.new(2) { create_user(name: "Limit RHS") }
+
+      users = (query.with_name("Limit LHS") | query.with_name("Limit RHS")).first(3).to_a
+
+      users.size.should eq 3
+    end
+
     describe "subqueries" do
       it "queries on membership in a set" do
         included = create_user(email: "included-#{UUID.random}")
diff --git a/src/query_builder.cr b/src/query_builder.cr
index 04815f7..31e22ca 100644
--- a/src/query_builder.cr
+++ b/src/query_builder.cr
@@ -1052,7 +1052,7 @@ module Interro
           str << ' ' << @combinator << ' '
           str << rhs
           if @limit
-            str << "LIMIT $" << (arg_count += 1)
+            str << " LIMIT $" << (arg_count += 1)
           end
         end
       end

From fa66bb1c9d004e5097ed0066a99d558f1903872b Mon Sep 17 00:00:00 2001
From: Martyn Loughran <martyn@mloughran.com>
Date: Sun, 16 Aug 2026 12:47:39 +0100
Subject: [PATCH 2/2] Fix SQL emitted for INTERSECT query

The & combinator used the wrong keyword, resulting in an error like:

> syntax error at or near "INTERSECTION" (PQ::PQError)
---
 spec/interro_spec.cr | 10 ++++++++++
 src/query_builder.cr |  2 +-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/spec/interro_spec.cr b/spec/interro_spec.cr
index 1e0d451..7d7daca 100644
--- a/spec/interro_spec.cr
+++ b/spec/interro_spec.cr
@@ -806,6 +806,16 @@ describe Interro do
       users.should_not contain excluded
     end
 
+    it "can run INTERSECT queries" do
+      both = create_user(name: "Both")
+      only_lhs = create_user(name: "Both", email: "lhs-only-#{UUID.random}@example.com")
+
+      users = (query.with_name("Both") & query.with_id(both.id)).to_a
+
+      users.should contain both
+      users.should_not contain only_lhs
+    end
+
     it "can limit compound queries" do
       Array.new(2) { create_user(name: "Limit LHS") }
       Array.new(2) { create_user(name: "Limit RHS") }
diff --git a/src/query_builder.cr b/src/query_builder.cr
index 31e22ca..8dd7d3a 100644
--- a/src/query_builder.cr
+++ b/src/query_builder.cr
@@ -258,7 +258,7 @@ module Interro
     end
 
     def &(other : self) : CompoundQuery
-      CompoundQuery.new(self, "INTERSECTION", other, connection(CONFIG.read_db))
+      CompoundQuery.new(self, "INTERSECT", other, connection(CONFIG.read_db))
     end
 
     def -(other : self) : CompoundQuery