support filtering table definitions

builder/table.go

@@ -1,17 +1,20 @@
 package builder
 
 import (
+	"log"
 	"strconv"
 
 	"github.com/go-rel/rel"
 )
 
 type ColumnMapper func(*rel.Column) (string, int, int)
+type DefinitionFilter func(table rel.Table, def rel.TableDefinition) (bool, string)
 
 // Table builder.
 type Table struct {
-	BufferFactory BufferFactory
-	ColumnMapper  ColumnMapper
+	BufferFactory    BufferFactory
+	ColumnMapper     ColumnMapper
+	DefinitionFilter DefinitionFilter
 }
 
 // Build SQL query for table creation and modification.
@@ -36,17 +39,19 @@ func (t Table) Build(table rel.Table) string {
 
 // WriteCreateTable query to buffer.
 func (t Table) WriteCreateTable(buffer *Buffer, table rel.Table) {
+	defs := t.definitions(table)
+
 	buffer.WriteString("CREATE TABLE ")
 
 	if table.Optional {
 		buffer.WriteString("IF NOT EXISTS ")
 	}
 
 	buffer.WriteEscape(table.Name)
-	if len(table.Definitions) > 0 {
+	if len(defs) > 0 {
 		buffer.WriteString(" (")
 
-		for i, def := range table.Definitions {
+		for i, def := range defs {
 			if i > 0 {
 				buffer.WriteString(", ")
 			}
@@ -68,7 +73,9 @@ func (t Table) WriteCreateTable(buffer *Buffer, table rel.Table) {
 
 // WriteAlterTable query to buffer.
 func (t Table) WriteAlterTable(buffer *Buffer, table rel.Table) {
-	for _, def := range table.Definitions {
+	defs := t.definitions(table)
+
+	for _, def := range defs {
 		buffer.WriteString("ALTER TABLE ")
 		buffer.WriteEscape(table.Name)
 		buffer.WriteByte(' ')
@@ -228,3 +235,23 @@ func (t Table) WriteOptions(buffer *Buffer, options string) {
 	buffer.WriteByte(' ')
 	buffer.WriteString(options)
 }
+
+func (t Table) definitions(table rel.Table) []rel.TableDefinition {
+	if t.DefinitionFilter == nil {
+		return table.Definitions
+	}
+
+	result := []rel.TableDefinition{}
+
+	for _, def := range table.Definitions {
+		ok, reason := t.DefinitionFilter(table, def)
+
+		if ok {
+			result = append(result, def)
+		} else {
+			log.Print("[REL] An unsupported table definition has been excluded: " + reason)
+		}
+	}
+
+	return result
+}

builder/table_test.go

@@ -133,3 +133,82 @@ func TestTable_Build(t *testing.T) {
 		})
 	}
 }
+
+func TestTable_BuildWithDefinitionFilter(t *testing.T) {
+	var (
+		definitionFilter = func(table rel.Table, def rel.TableDefinition) (bool, string) {
+			_, ok := def.(rel.Key)
+			// https://www.sqlite.org/omitted.html
+			// > Only the RENAME TABLE, ADD COLUMN, RENAME COLUMN, and DROP COLUMN variants of the ALTER TABLE command are supported.
+			if ok && table.Op == rel.SchemaAlter {
+				return false, "adapter does not support adding keys when modifying tables"
+			}
+
+			return true, ""
+		}
+		tableBuilder = Table{
+			BufferFactory:    BufferFactory{InlineValues: true, BoolTrueValue: "true", BoolFalseValue: "false", Quoter: Quote{IDPrefix: "`", IDSuffix: "`", IDSuffixEscapeChar: "`", ValueQuote: "'", ValueQuoteEscapeChar: "'"}},
+			ColumnMapper:     sql.ColumnMapper,
+			DefinitionFilter: definitionFilter,
+		}
+	)
+
+	tests := []struct {
+		result string
+		table  rel.Table
+	}{
+		{
+			result: "CREATE TABLE `columns` (`bool` BOOL NOT NULL DEFAULT false, `int` INT(11) UNSIGNED, `bigint` BIGINT(20) UNSIGNED, `float` FLOAT(24) UNSIGNED, `decimal` DECIMAL(6,2) UNSIGNED, `string` VARCHAR(144) UNIQUE, `text` TEXT(1000), `date` DATE, `datetime` DATETIME DEFAULT '2020-01-01 01:00:00', `time` TIME, `blob` blob, PRIMARY KEY (`int`), FOREIGN KEY (`int`, `string`) REFERENCES `products` (`id`, `name`) ON DELETE CASCADE ON UPDATE CASCADE, UNIQUE `date_unique` (`date`)) Engine=InnoDB;",
+			table: rel.Table{
+				Op:   rel.SchemaCreate,
+				Name: "columns",
+				Definitions: []rel.TableDefinition{
+					rel.Column{Name: "bool", Type: rel.Bool, Required: true, Default: false},
+					rel.Column{Name: "int", Type: rel.Int, Limit: 11, Unsigned: true},
+					rel.Column{Name: "bigint", Type: rel.BigInt, Limit: 20, Unsigned: true},
+					rel.Column{Name: "float", Type: rel.Float, Precision: 24, Unsigned: true},
+					rel.Column{Name: "decimal", Type: rel.Decimal, Precision: 6, Scale: 2, Unsigned: true},
+					rel.Column{Name: "string", Type: rel.String, Limit: 144, Unique: true},
+					rel.Column{Name: "text", Type: rel.Text, Limit: 1000},
+					rel.Column{Name: "date", Type: rel.Date},
+					rel.Column{Name: "datetime", Type: rel.DateTime, Default: time.Date(2020, 1, 1, 1, 0, 0, 0, time.UTC)},
+					rel.Column{Name: "time", Type: rel.Time},
+					rel.Column{Name: "blob", Type: "blob"},
+					rel.Key{Columns: []string{"int"}, Type: rel.PrimaryKey},
+					rel.Key{Columns: []string{"int", "string"}, Type: rel.ForeignKey, Reference: rel.ForeignKeyReference{Table: "products", Columns: []string{"id", "name"}, OnDelete: "CASCADE", OnUpdate: "CASCADE"}},
+					rel.Key{Columns: []string{"date"}, Name: "date_unique", Type: rel.UniqueKey},
+				},
+				Options: "Engine=InnoDB",
+			},
+		},
+		{
+			result: "ALTER TABLE `columns` ADD COLUMN `verified` BOOL;ALTER TABLE `columns` RENAME COLUMN `string` TO `name`;ALTER TABLE `columns` ;ALTER TABLE `columns` DROP COLUMN `blob`;",
+			table: rel.Table{
+				Op:   rel.SchemaAlter,
+				Name: "columns",
+				Definitions: []rel.TableDefinition{
+					rel.Column{Name: "verified", Type: rel.Bool, Op: rel.SchemaCreate},
+					rel.Column{Name: "string", Rename: "name", Op: rel.SchemaRename},
+					rel.Column{Name: "bool", Type: rel.Int, Op: rel.SchemaAlter},
+					rel.Column{Name: "blob", Op: rel.SchemaDrop},
+				},
+			},
+		},
+		{
+			result: "",
+			table: rel.Table{
+				Op:   rel.SchemaAlter,
+				Name: "transactions",
+				Definitions: []rel.TableDefinition{
+					rel.Key{Op: rel.SchemaCreate, Columns: []string{"user_id"}, Type: rel.ForeignKey, Reference: rel.ForeignKeyReference{Table: "products", Columns: []string{"id", "name"}, OnDelete: "CASCADE", OnUpdate: "CASCADE"}},
+				},
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.result, func(t *testing.T) {
+			assert.Equal(t, test.result, tableBuilder.Build(test.table))
+		})
+	}
+}