fix: preserve INCLUDE columns on CREATE INDEX (#385)

internal/diff/index.go

@@ -121,6 +121,18 @@ func generateIndexSQLWithName(index *ir.Index, indexName string, targetSchema st
 	}
 	builder.WriteString(")")
 
+	// INCLUDE columns (non-key columns stored in the index)
+	if len(index.IncludeColumns) > 0 {
+		builder.WriteString(" INCLUDE (")
+		for i, col := range index.IncludeColumns {
+			if i > 0 {
+				builder.WriteString(", ")
+			}
+			builder.WriteString(col)
+		}
+		builder.WriteString(")")
+	}
+
 	// NULLS NOT DISTINCT for unique indexes (PostgreSQL 15+)
 	if index.NullsNotDistinct && index.Type == ir.IndexTypeUnique {
 		builder.WriteString(" NULLS NOT DISTINCT")

internal/diff/table.go

@@ -1511,6 +1511,16 @@ func indexesStructurallyEqual(oldIndex, newIndex *ir.Index) bool {
 		}
 	}
 
+	// Compare INCLUDE columns
+	if len(oldIndex.IncludeColumns) != len(newIndex.IncludeColumns) {
+		return false
+	}
+	for i, oldCol := range oldIndex.IncludeColumns {
+		if oldCol != newIndex.IncludeColumns[i] {
+			return false
+		}
+	}
+
 	return true
 }
 

ir/inspector.go

@@ -746,16 +746,17 @@ func (i *Inspector) buildIndexes(ctx context.Context, schema *IR, targetSchema s
 		}
 
 		index := &Index{
-			Schema:       schemaName,
-			Table:        tableName,
-			Name:         indexName,
-			Type:         indexType,
-			Method:       method,
-			IsPartial:    isPartial,
-			IsExpression: hasExpressions,
-			Where:        "",
-			Comment:      comment,
-			Columns:      []*IndexColumn{},
+			Schema:         schemaName,
+			Table:          tableName,
+			Name:           indexName,
+			Type:           indexType,
+			Method:         method,
+			IncludeColumns: indexRow.IncludeColumns,
+			IsPartial:      isPartial,
+			IsExpression:   hasExpressions,
+			Where:          "",
+			Comment:        comment,
+			Columns:        []*IndexColumn{},
 		}
 
 		// Check for NULLS NOT DISTINCT (PostgreSQL 15+)

ir/ir.go

@@ -251,11 +251,12 @@ type Index struct {
 	Type         IndexType      `json:"type"`
 	Method       string         `json:"method"` // btree, hash, gin, gist, etc.
 	Columns      []*IndexColumn `json:"columns"`
-	IsPartial        bool   `json:"is_partial"`                   // has a WHERE clause
-	IsExpression     bool   `json:"is_expression"`                // functional/expression index
-	Where            string `json:"where,omitempty"`              // partial index condition
-	NullsNotDistinct bool   `json:"nulls_not_distinct,omitempty"` // NULLS NOT DISTINCT (PG15+)
-	Comment          string `json:"comment,omitempty"`
+	IncludeColumns   []string `json:"include_columns,omitempty"`     // INCLUDE columns (non-key)
+	IsPartial        bool     `json:"is_partial"`                   // has a WHERE clause
+	IsExpression     bool     `json:"is_expression"`                // functional/expression index
+	Where            string   `json:"where,omitempty"`              // partial index condition
+	NullsNotDistinct bool     `json:"nulls_not_distinct,omitempty"` // NULLS NOT DISTINCT (PG15+)
+	Comment          string   `json:"comment,omitempty"`
 }
 
 // IndexColumn represents a column within an index

ir/queries/queries.sql

@@ -436,27 +436,32 @@ WITH index_base AS (
             ELSE false
         END as has_expressions,
         COALESCE(d.description, '') AS index_comment,
+        idx.indnkeyatts as num_key_columns,
         idx.indnatts as num_columns,
         ARRAY(
             SELECT pg_get_indexdef(idx.indexrelid, k::int, true)
-            FROM generate_series(1, idx.indnatts) k
+            FROM generate_series(1, idx.indnkeyatts) k
         ) as column_definitions,
         ARRAY(
             SELECT
                 CASE
                     WHEN (idx.indoption[k-1] & 1) = 1 THEN 'DESC'
                     ELSE 'ASC'
                 END
-            FROM generate_series(1, idx.indnatts) k
+            FROM generate_series(1, idx.indnkeyatts) k
         ) as column_directions,
         ARRAY(
             SELECT CASE
                 WHEN opc.opcdefault THEN ''  -- Omit default operator classes
                 ELSE COALESCE(opc.opcname, '')
             END
-            FROM generate_series(1, idx.indnatts) k
+            FROM generate_series(1, idx.indnkeyatts) k
             LEFT JOIN pg_opclass opc ON opc.oid = idx.indclass[k-1]
-        ) as column_opclasses
+        ) as column_opclasses,
+        ARRAY(
+            SELECT pg_get_indexdef(idx.indexrelid, k::int, true)
+            FROM generate_series(idx.indnkeyatts + 1, idx.indnatts) k
+        ) as include_columns
     FROM pg_index idx
     JOIN pg_class i ON i.oid = idx.indexrelid
     JOIN pg_class t ON t.oid = idx.indrelid
@@ -488,10 +493,12 @@ SELECT
     sp.partial_predicate,
     ib.has_expressions,
     ib.index_comment,
+    ib.num_key_columns,
     ib.num_columns,
     ib.column_definitions,
     ib.column_directions,
-    ib.column_opclasses
+    ib.column_opclasses,
+    ib.include_columns
 FROM index_base ib
 CROSS JOIN LATERAL (
     SELECT

testdata/diff/create_index/add_index/diff.sql

@@ -7,6 +7,8 @@ CREATE TABLE IF NOT EXISTS users (
 
 CREATE INDEX IF NOT EXISTS idx_users_email ON users (email varchar_pattern_ops);
 
+CREATE INDEX IF NOT EXISTS idx_users_email_include ON users (email) INCLUDE (name);
+
 CREATE UNIQUE INDEX IF NOT EXISTS idx_users_email_unique ON users (email) NULLS NOT DISTINCT;
 
 CREATE INDEX IF NOT EXISTS idx_users_id ON users (id);

testdata/diff/create_index/add_index/new.sql

@@ -12,3 +12,5 @@ CREATE INDEX idx_users_id ON public.users (id);
 CREATE INDEX "public.idx_users" ON public.users (email, name);
 -- Test NULLS NOT DISTINCT (issue #355)
 CREATE UNIQUE INDEX idx_users_email_unique ON public.users (email) NULLS NOT DISTINCT;
+-- Test INCLUDE columns (issue #385)
+CREATE INDEX idx_users_email_include ON public.users (email) INCLUDE (name);

testdata/diff/create_index/add_index/plan.json

@@ -20,6 +20,12 @@
           "operation": "create",
           "path": "public.users.idx_users_email"
         },
+        {
+          "sql": "CREATE INDEX IF NOT EXISTS idx_users_email_include ON users (email) INCLUDE (name);",
+          "type": "table.index",
+          "operation": "create",
+          "path": "public.users.idx_users_email_include"
+        },
         {
           "sql": "CREATE UNIQUE INDEX IF NOT EXISTS idx_users_email_unique ON users (email) NULLS NOT DISTINCT;",
           "type": "table.index",

testdata/diff/create_index/add_index/plan.sql

@@ -7,6 +7,8 @@ CREATE TABLE IF NOT EXISTS users (
 
 CREATE INDEX IF NOT EXISTS idx_users_email ON users (email varchar_pattern_ops);
 
+CREATE INDEX IF NOT EXISTS idx_users_email_include ON users (email) INCLUDE (name);
+
 CREATE UNIQUE INDEX IF NOT EXISTS idx_users_email_unique ON users (email) NULLS NOT DISTINCT;
 
 CREATE INDEX IF NOT EXISTS idx_users_id ON users (id);

testdata/diff/create_index/add_index/plan.txt

@@ -6,6 +6,7 @@ Summary by type:
 Tables:
   + users
     + idx_users_email (index)
+    + idx_users_email_include (index)
     + idx_users_email_unique (index)
     + idx_users_id (index)
     + idx_users_name (index)
@@ -23,6 +24,8 @@ CREATE TABLE IF NOT EXISTS users (
 
 CREATE INDEX IF NOT EXISTS idx_users_email ON users (email varchar_pattern_ops);
 
+CREATE INDEX IF NOT EXISTS idx_users_email_include ON users (email) INCLUDE (name);
+
 CREATE UNIQUE INDEX IF NOT EXISTS idx_users_email_unique ON users (email) NULLS NOT DISTINCT;
 
 CREATE INDEX IF NOT EXISTS idx_users_id ON users (id);