Convert inline CHECK constraints

Convert SQL `CREATE TABLE` statements with inline `CHECK` constraints
like this:

```
CREATE TABLE foo(a int CHECK (a > 0))
```

to `OpCreateTable` operations.

pkg/sql2pgroll/create_table.go

@@ -97,6 +97,7 @@ func convertColumnDef(col *pgq.ColumnDef) (*migrations.Column, error) {
 
 	// Convert column constraints
 	var notNull, pk, unique bool
+	var check *migrations.CheckConstraint
 	for _, c := range col.GetConstraints() {
 		switch c.GetConstraint().GetContype() {
 		case pgq.ConstrType_CONSTR_NULL:
@@ -115,7 +116,11 @@ func convertColumnDef(col *pgq.ColumnDef) (*migrations.Column, error) {
 			pk = true
 			notNull = true
 		case pgq.ConstrType_CONSTR_CHECK:
-			if !canConvertCheckConstraint(c.GetConstraint()) {
+			check, err = convertInlineCheckConstraint(c.GetConstraint())
+			if err != nil {
+				return nil, fmt.Errorf("error converting inline check constraint: %w", err)
+			}
+			if check == nil {
 				return nil, nil
 			}
 		case pgq.ConstrType_CONSTR_FOREIGN:
@@ -130,6 +135,7 @@ func convertColumnDef(col *pgq.ColumnDef) (*migrations.Column, error) {
 		Type:     typeString,
 		Nullable: !notNull,
 		Pk:       pk,
+		Check:    check,
 		Unique:   unique,
 	}, nil
 }
@@ -164,3 +170,18 @@ func canConvertPrimaryKeyConstraint(constraint *pgq.Constraint) bool {
 		return true
 	}
 }
+
+func convertInlineCheckConstraint(constraint *pgq.Constraint) (*migrations.CheckConstraint, error) {
+	if !canConvertCheckConstraint(constraint) {
+		return nil, nil
+	}
+
+	expr, err := pgq.DeparseExpr(constraint.GetRawExpr())
+	if err != nil {
+		return nil, fmt.Errorf("failed to deparse CHECK expression: %w", err)
+	}
+
+	return &migrations.CheckConstraint{
+		Constraint: expr,
+	}, nil
+}

pkg/sql2pgroll/create_table_test.go

@@ -60,6 +60,10 @@ func TestConvertCreateTableStatements(t *testing.T) {
 			sql:        "CREATE TABLE foo(a text[5][3])",
 			expectedOp: expect.CreateTableOp9,
 		},
+		{
+			sql:        "CREATE TABLE foo(a int CHECK (a > 0))",
+			expectedOp: expect.CreateTableOp10,
+		},
 	}
 
 	for _, tc := range tests {

pkg/sql2pgroll/expect/create_table.go

@@ -102,3 +102,17 @@ var CreateTableOp9 = &migrations.OpCreateTable{
 		},
 	},
 }
+
+var CreateTableOp10 = &migrations.OpCreateTable{
+	Name: "foo",
+	Columns: []migrations.Column{
+		{
+			Name:     "a",
+			Type:     "int",
+			Nullable: true,
+			Check: &migrations.CheckConstraint{
+				Constraint: "a > 0",
+			},
+		},
+	},
+}