[feat] 新增表结构操作

2025-03-24 16:58:37 +08:00
parent f9ca4a49ce
commit 764eccfafd
14 changed files with 2606 additions and 0 deletions
@@ -0,0 +1,213 @@
+package postgres
+
+import (
+	"strings"
+
+	"git.fsdpf.net/go/db/v2"
+	"git.fsdpf.net/go/db/v2/dialect/postgres"
+	"git.fsdpf.net/go/db/v2/internal/sb"
+	"git.fsdpf.net/go/db/v2/schema"
+	"git.fsdpf.net/go/db/v2/sqlgen"
+)
+
+type Postgres struct {
+	db  *db.Database
+	esg sqlgen.ExpressionSQLGenerator
+}
+
+var pgDefaultModifiers = []string{
+	"Nullable", "Default", "Increment", "Comment",
+}
+var pgSerials = []string{
+	"bigInteger", "integer", "smallInteger",
+}
+
+func (this Postgres) GetColumnListing(table string) ([]string, error) {
+	cols := []string{}
+	err := this.db.From(db.S("information_schema").Table("columns")).Where(
+		db.C("table_name").Eq(table),
+		db.C("table_schema").Eq(db.L("current_database()")),
+	).Pluck(&cols, "column_name")
+	return cols, err
+}
+
+func (this Postgres) TableExists(table string) (bool, error) {
+	result, err := this.db.From(db.S("information_schema").Table("tables")).Where(db.Ex{
+		"table_name":   table,
+		"table_schema": db.L("current_database()"),
+	}).Count()
+	return result > 0, err
+}
+
+func (this Postgres) CompileCreate(bp *schema.Blueprint) []string {
+	temporary := db.L("CREATE")
+	if bp.IsTemporary() {
+		temporary = db.L("CREATE TEMPORARY")
+	}
+	columns := strings.Join(this.getAddedColumns(bp), ",\n")
+	sql := this.GenerateSQL("? TABLE ? (\n?\n)", temporary, db.T(bp.GetTable()), db.L(columns))
+	return []string{sql}
+}
+
+func (this Postgres) CompileAdd(bp *schema.Blueprint) []string {
+	columns := strings.Join(schema.PrefixArray("ADD COLUMN", this.getAddedColumns(bp)), ",\n")
+	sql := this.GenerateSQL("ALTER TABLE ?\n?", db.T(bp.GetTable()), db.L(columns))
+	return []string{sql}
+}
+
+func (this Postgres) CompileChange(bp *schema.Blueprint) []string {
+	columns := strings.Join(schema.PrefixArray("ALTER COLUMN", this.getChangedColumns(bp)), ",\n")
+	sql := this.GenerateSQL("ALTER TABLE ?\n?", db.T(bp.GetTable()), db.L(columns))
+	return []string{sql}
+}
+
+func (this Postgres) CompileDropColumn(bp *schema.Blueprint) []string {
+	columns := []string{}
+	for _, item := range bp.GetCommands() {
+		if item.Type != "dropColumn" {
+			continue
+		}
+		for _, col := range item.Columns {
+			columns = append(columns, this.GenerateSQL("DROP COLUMN ?", db.C(col)))
+		}
+	}
+	sql := this.GenerateSQL("ALTER TABLE ?\n?", db.T(bp.GetTable()), db.L(strings.Join(columns, ",\n")))
+	return []string{sql}
+}
+
+func (this Postgres) CompileDrop(bp *schema.Blueprint) []string {
+	return []string{this.GenerateSQL("DROP TABLE ?", db.T(bp.GetTable()))}
+}
+
+func (this Postgres) CompileDropIfExists(bp *schema.Blueprint) []string {
+	return []string{this.GenerateSQL("DROP TABLE IF EXISTS ?", db.T(bp.GetTable()))}
+}
+
+func (this Postgres) CompileRename(bp *schema.Blueprint) []string {
+	toName := ""
+	commands := bp.GetCommands()
+	if len(commands) == 0 {
+		panic("new table undefined")
+	}
+	toName = bp.GetCommands()[0].To
+	if toName == "" {
+		panic("new table undefined")
+	}
+	return []string{this.GenerateSQL("ALTER TABLE ? RENAME TO ?", db.T(bp.GetTable()), db.T(toName))}
+}
+
+func (this Postgres) addModifiers(sql string, bp *schema.Blueprint, column *schema.ColumnDefinition) string {
+	for _, modifier := range pgDefaultModifiers {
+		sql += this.GetColumnModifier(modifier, bp, column)
+	}
+	return sql
+}
+
+func (this Postgres) GetColumnType(column *schema.ColumnDefinition) string {
+	switch column.Type {
+	case "char":
+		return this.GenerateSQL("char(?)", column.Length)
+	case "string":
+		return this.GenerateSQL("varchar(?)", column.Length)
+	case "text":
+		return "text"
+	case "integer":
+		return "integer"
+	case "bigInteger":
+		return "bigint"
+	case "smallInteger":
+		return "smallint"
+	case "decimal":
+		return this.GenerateSQL("numeric(?,?)", column.Total, column.Places)
+	case "boolean":
+		return "boolean"
+	case "enum":
+		return this.GenerateSQL("varchar(?)", column.Length) // PostgreSQL uses custom types or check constraints
+	case "json":
+		return "json"
+	case "binary":
+		return "bytea"
+	case "datetime":
+		return "timestamp without time zone"
+	case "timestamp":
+		return "timestamp with time zone"
+	case "date":
+		return "date"
+	case "time":
+		return "time"
+	case "year":
+		return "integer"
+	case "uuid":
+		return "uuid"
+	}
+	panic("Unsupported data type: " + column.Type)
+}
+
+func (this Postgres) GetColumnModifier(modifier string, bp *schema.Blueprint, column *schema.ColumnDefinition) string {
+	switch modifier {
+	case "Nullable":
+		if column.IsNullable() {
+			return " NULL"
+		}
+		return " NOT NULL"
+	case "Default":
+		v := column.GetDefault()
+		if v == nil {
+			if column.IsUseCurrent() {
+				return " DEFAULT CURRENT_TIMESTAMP"
+			}
+			return ""
+		}
+		if column.IsUseCurrent() {
+			return this.GenerateSQL(" DEFAULT CURRENT_TIMESTAMP ?", v)
+		}
+		return this.GenerateSQL(" DEFAULT ?", v)
+	case "Increment":
+		if column.IsAutoIncrement() {
+			switch column.Type {
+			case "integer":
+				return " SERIAL PRIMARY KEY"
+			case "bigInteger":
+				return " BIGSERIAL PRIMARY KEY"
+			case "smallInteger":
+				return " SMALLSERIAL PRIMARY KEY"
+			}
+		}
+	case "Comment":
+		// PostgreSQL handles comments separately via COMMENT ON
+		return ""
+	}
+	return ""
+}
+
+func (this Postgres) getAddedColumns(bp *schema.Blueprint) (columns []string) {
+	for _, column := range bp.GetAddedColumns() {
+		sql := this.GenerateSQL("? ?", db.C(column.Name), db.L(this.GetColumnType(column)))
+		columns = append(columns, this.addModifiers(sql, bp, column))
+	}
+	return
+}
+
+func (this Postgres) getChangedColumns(bp *schema.Blueprint) (columns []string) {
+	for _, column := range bp.GetChangedColumns() {
+		sql := this.GenerateSQL("? TYPE ?", db.C(column.Name), db.L(this.GetColumnType(column)))
+		columns = append(columns, this.addModifiers(sql, bp, column))
+	}
+	return
+}
+
+func (this Postgres) GenerateSQL(sql string, args ...any) string {
+	sb := sb.NewSQLBuilder(false)
+	this.esg.Generate(sb, db.L(sql, args...))
+	result, _, _ := sb.ToSQL()
+	return result
+}
+
+func init() {
+	schema.RegisterDialect("postgres", func(db *db.Database) schema.Schema {
+		return &Postgres{
+			db:  db,
+			esg: sqlgen.NewExpressionSQLGenerator("postgres", postgres.DialectOptions()),
+		}
+	})
+}