fix: emit per-child column overrides in PARTITION OF (#499)

internal/diff/diff.go

@@ -271,6 +271,7 @@ type ddlDiff struct {
 	addedTables               []*ir.Table
 	droppedTables             []*ir.Table
 	modifiedTables            []*tableDiff
+	allNewTables              map[string]*ir.Table
 	addedViews                []*ir.View
 	droppedViews              []*ir.View
 	modifiedViews             []*viewDiff
@@ -626,6 +627,8 @@ func GenerateMigrationWithOptions(oldIR, newIR *ir.IR, targetSchema string, qual
 		}
 	}
 
+	diff.allNewTables = newTables
+
 	// Compare functions across all schemas
 	oldFunctions := make(map[string]*ir.Function)
 	newFunctions := make(map[string]*ir.Function)
@@ -1823,7 +1826,7 @@ func (d *ddlDiff) generateCreateSQL(targetSchema string, collector *diffCollecto
 	}
 
 	// Create tables WITHOUT function/domain dependencies first (functions may reference these)
-	deferredPolicies1, deferredConstraints1 := generateCreateTablesSQL(tablesWithoutDeps, targetSchema, collector, existingTables, shouldDeferPolicy, d.suppressedInlineFKs)
+	deferredPolicies1, deferredConstraints1 := generateCreateTablesSQL(tablesWithoutDeps, targetSchema, collector, existingTables, shouldDeferPolicy, d.suppressedInlineFKs, d.allNewTables)
 
 	// Build view lookup - needed for detecting functions that depend on views
 	newViewLookup := buildViewLookup(d.addedViews)
@@ -1877,7 +1880,7 @@ func (d *ddlDiff) generateCreateSQL(targetSchema string, collector *diffCollecto
 	generateCreateProceduresSQL(d.addedProcedures, targetSchema, collector)
 
 	// Create tables WITH function/domain dependencies (now that functions and deferred domains exist)
-	deferredPolicies2, deferredConstraints2 := generateCreateTablesSQL(tablesWithDeps, targetSchema, collector, existingTables, shouldDeferPolicy, d.suppressedInlineFKs)
+	deferredPolicies2, deferredConstraints2 := generateCreateTablesSQL(tablesWithDeps, targetSchema, collector, existingTables, shouldDeferPolicy, d.suppressedInlineFKs, d.allNewTables)
 
 	// Emit COMMENT ON SEQUENCE for sequences created implicitly via CREATE TABLE (SERIAL/BIGSERIAL).
 	// These were skipped from addedSequences but their comments must still be deployed.

internal/diff/qualify_schema_test.go

@@ -55,15 +55,15 @@ func TestQualifySchema_TableAndColumnType(t *testing.T) {
 	}
 	empty := map[string]bool{}
 
-	def, _ := generateTableSQL(table, "public", false, empty, empty, empty)
+	def, _ := generateTableSQL(table, "public", false, empty, empty, empty, nil)
 	if !strings.Contains(def, "CREATE TABLE IF NOT EXISTS account (") {
 		t.Errorf("default should use the bare table name: %q", def)
 	}
 	if strings.Contains(def, "public.account") || strings.Contains(def, "public.user_kind") {
 		t.Errorf("default should not qualify the target schema: %q", def)
 	}
 
-	qualified, _ := generateTableSQL(table, "public", true, empty, empty, empty)
+	qualified, _ := generateTableSQL(table, "public", true, empty, empty, empty, nil)
 	if !strings.Contains(qualified, "CREATE TABLE IF NOT EXISTS public.account (") {
 		t.Errorf("forced qualification should qualify the table name: %q", qualified)
 	}

internal/diff/table.go

@@ -413,6 +413,7 @@ func generateCreateTablesSQL(
 	existingTables map[string]bool,
 	shouldDeferPolicy func(*ir.RLSPolicy) bool,
 	suppressedInlineFKs map[string]bool,
+	allNewTables map[string]*ir.Table,
 ) ([]*ir.RLSPolicy, []*deferredConstraint) {
 	var deferredPolicies []*ir.RLSPolicy
 	var deferredConstraints []*deferredConstraint
@@ -421,7 +422,7 @@ func generateCreateTablesSQL(
 	// Process tables in the provided order (already topologically sorted)
 	for _, table := range tables {
 		// Create the table, deferring FK constraints that reference not-yet-created tables
-		sql, tableDeferred := generateTableSQL(table, targetSchema, collector.qualifySchema, createdTables, existingTables, suppressedInlineFKs)
+		sql, tableDeferred := generateTableSQL(table, targetSchema, collector.qualifySchema, createdTables, existingTables, suppressedInlineFKs, allNewTables)
 		deferredConstraints = append(deferredConstraints, tableDeferred...)
 
 		// Create context for this statement
@@ -759,7 +760,7 @@ func generateDropTablesSQL(tables []*ir.Table, targetSchema string, collector *d
 }
 
 // generateTableSQL generates CREATE TABLE statement and returns any deferred FK constraints
-func generateTableSQL(table *ir.Table, targetSchema string, qualifySchema bool, createdTables map[string]bool, existingTables map[string]bool, suppressedInlineFKs map[string]bool) (string, []*deferredConstraint) {
+func generateTableSQL(table *ir.Table, targetSchema string, qualifySchema bool, createdTables map[string]bool, existingTables map[string]bool, suppressedInlineFKs map[string]bool, allTables map[string]*ir.Table) (string, []*deferredConstraint) {
 	// Only include table name without schema if it's in the target schema (unless
 	// forced qualification is on).
 	tableName := ir.QualifyEntityNameWithQuotesMode(table.Schema, table.Name, targetSchema, qualifySchema)
@@ -774,7 +775,44 @@ func generateTableSQL(table *ir.Table, targetSchema string, qualifySchema bool,
 		}
 		parentName := ir.QualifyEntityNameWithQuotesMode(parentSchema, table.PartitionOf, targetSchema, qualifySchema)
 
-		// Include child-specific constraints in the PARTITION OF statement.
+		// Include child-specific column overrides and constraints in the PARTITION OF statement.
+		var elementParts []string
+
+		// Detect per-child column overrides (DEFAULT, NOT NULL) by comparing against the parent.
+		parentKey := parentSchema + "." + table.PartitionOf
+		if parentTable, ok := allTables[parentKey]; ok {
+			parentCols := make(map[string]*ir.Column, len(parentTable.Columns))
+			for _, col := range parentTable.Columns {
+				parentCols[col.Name] = col
+			}
+			for _, col := range table.Columns {
+				parentCol := parentCols[col.Name]
+				if parentCol == nil {
+					continue
+				}
+				var overrides []string
+				childDefault := ""
+				parentDefault := ""
+				if col.DefaultValue != nil {
+					childDefault = *col.DefaultValue
+				}
+				if parentCol.DefaultValue != nil {
+					parentDefault = *parentCol.DefaultValue
+				}
+				if childDefault != parentDefault {
+					if col.DefaultValue != nil {
+						overrides = append(overrides, fmt.Sprintf("DEFAULT %s", *col.DefaultValue))
+					}
+				}
+				if !col.IsNullable && parentCol.IsNullable {
+					overrides = append(overrides, "NOT NULL")
+				}
+				if len(overrides) > 0 {
+					elementParts = append(elementParts, fmt.Sprintf("    %s %s", ir.QuoteIdentifier(col.Name), strings.Join(overrides, " ")))
+				}
+			}
+		}
+
 		inlineConstraints := getInlineConstraintsForTable(table)
 		var constraintParts []string
 		var deferred []*deferredConstraint
@@ -800,10 +838,11 @@ func generateTableSQL(table *ir.Table, targetSchema string, qualifySchema bool,
 			createPrefix = "CREATE UNLOGGED TABLE IF NOT EXISTS"
 		}
 
+		allParts := append(elementParts, constraintParts...)
 		var sql string
-		if len(constraintParts) > 0 {
+		if len(allParts) > 0 {
 			sql = fmt.Sprintf("%s %s PARTITION OF %s (\n%s\n) %s;",
-				createPrefix, tableName, parentName, strings.Join(constraintParts, ",\n"), table.PartitionBound)
+				createPrefix, tableName, parentName, strings.Join(allParts, ",\n"), table.PartitionBound)
 		} else {
 			sql = fmt.Sprintf("%s %s PARTITION OF %s %s;", createPrefix, tableName, parentName, table.PartitionBound)
 		}

testdata/diff/create_table/issue_499_partition_column_overrides/diff.sql

@@ -0,0 +1,4 @@
+CREATE TABLE IF NOT EXISTS orders_us PARTITION OF orders (
+    priority DEFAULT 10,
+    notes NOT NULL
+) FOR VALUES IN ('us');

testdata/diff/create_table/issue_499_partition_column_overrides/new.sql

@@ -0,0 +1,14 @@
+CREATE TABLE public.orders (
+    id bigint NOT NULL,
+    region text NOT NULL,
+    priority integer DEFAULT 0,
+    notes text
+) PARTITION BY LIST (region);
+
+CREATE TABLE public.orders_eu PARTITION OF public.orders
+    FOR VALUES IN ('eu');
+
+CREATE TABLE public.orders_us PARTITION OF public.orders (
+    priority DEFAULT 10,
+    notes NOT NULL
+) FOR VALUES IN ('us');

testdata/diff/create_table/issue_499_partition_column_overrides/old.sql

@@ -0,0 +1,9 @@
+CREATE TABLE public.orders (
+    id bigint NOT NULL,
+    region text NOT NULL,
+    priority integer DEFAULT 0,
+    notes text
+) PARTITION BY LIST (region);
+
+CREATE TABLE public.orders_eu PARTITION OF public.orders
+    FOR VALUES IN ('eu');

testdata/diff/create_table/issue_499_partition_column_overrides/plan.json

@@ -0,0 +1,20 @@
+{
+  "version": "1.0.0",
+  "pgschema_version": "1.11.1",
+  "created_at": "1970-01-01T00:00:00Z",
+  "source_fingerprint": {
+    "hash": "8872790ced32fbe419a3297dfdcd20a1b6e17650d2dcb1773161f505b66b2be8"
+  },
+  "groups": [
+    {
+      "steps": [
+        {
+          "sql": "CREATE TABLE IF NOT EXISTS orders_us PARTITION OF orders (\n    priority DEFAULT 10,\n    notes NOT NULL\n) FOR VALUES IN ('us');",
+          "type": "table",
+          "operation": "create",
+          "path": "public.orders_us"
+        }
+      ]
+    }
+  ]
+}

testdata/diff/create_table/issue_499_partition_column_overrides/plan.sql

@@ -0,0 +1,4 @@
+CREATE TABLE IF NOT EXISTS orders_us PARTITION OF orders (
+    priority DEFAULT 10,
+    notes NOT NULL
+) FOR VALUES IN ('us');

testdata/diff/create_table/issue_499_partition_column_overrides/plan.txt

@@ -0,0 +1,15 @@
+Plan: 1 to add.
+
+Summary by type:
+  tables: 1 to add
+
+Tables:
+  + orders_us
+
+DDL to be executed:
+--------------------------------------------------
+
+CREATE TABLE IF NOT EXISTS orders_us PARTITION OF orders (
+    priority DEFAULT 10,
+    notes NOT NULL
+) FOR VALUES IN ('us');