first commit

schema/builder.go

@@ -0,0 +1,128 @@
+package schema
+
+import (
+	"github.com/samber/lo"
+
+	"git.fsdpf.net/go/db"
+)
+
+type Builder struct {
+	Connection *db.Connection // The database connection instance
+	Grammar    IGrammar       // The schema grammar instance
+}
+
+func NewSchema(conn *db.Connection) *Builder {
+	var grammar IGrammar
+
+	switch conn.GetConfig().Driver {
+	case "mysql":
+		grammar = &MysqlGrammar{}
+	case "sqlite3":
+		grammar = &Sqlite3Grammar{}
+	}
+
+	return &Builder{
+		Connection: conn,
+		Grammar:    grammar,
+	}
+}
+
+// 判断数据表是否存在
+func (this *Builder) HasTable(table string) (bool, error) {
+	query := this.Grammar.CompileTableExists()
+	dbName := this.Connection.GetConfig().Database
+
+	count := 0
+
+	if _, err := this.Connection.Select(query, []any{table, dbName}, &count); err != nil || count == 0 {
+		return false, err
+	}
+
+	return true, nil
+}
+
+// 判断表字段是个存在
+func (this *Builder) HasColumns(table string, columns ...string) (bool, error) {
+	if tColumns, err := this.GetColumnListing(table); err != nil {
+		return false, err
+	} else {
+		for _, col := range columns {
+			if !lo.Contains(tColumns, col) {
+				return false, nil
+			}
+		}
+	}
+	return true, nil
+}
+
+// 判断数据库列是否存在
+func (this *Builder) GetColumnListing(table string) (columns []string, err error) {
+	query := this.Grammar.CompileColumnListing(table)
+	dbName := this.Connection.GetConfig().Database
+
+	items := []struct {
+		ID   int    `db:"id"`
+		Name string `db:"name"`
+	}{}
+
+	bindings := []any{table, dbName}
+
+	if this.Connection.GetConfig().Driver == "sqlite3" {
+		bindings = nil
+	}
+
+	if _, err := this.Connection.Select(query, bindings, &items); err != nil {
+		return nil, err
+	}
+
+	for _, item := range items {
+		columns = append(columns, item.Name)
+	}
+
+	return
+}
+
+// 修改表
+func (this *Builder) Table(table string, cb func(*Blueprint)) error {
+	bp := this.createBlueprint(table)
+	cb(bp)
+	return this.Build(bp)
+}
+
+// 创建表
+func (this *Builder) Create(table string, cb func(*Blueprint)) error {
+	bp := this.createBlueprint(table)
+	bp.Create()
+	cb(bp)
+	return this.Build(bp)
+}
+
+// 修改表名
+func (this *Builder) Rename(from, to string) error {
+	bp := this.createBlueprint(from)
+	bp.Rename(to)
+	return this.Build(bp)
+}
+
+// 删除表
+func (this *Builder) Drop(table string) error {
+	bp := this.createBlueprint(table)
+	bp.Drop()
+	return this.Build(bp)
+}
+
+// 删除表, 先判断再删除
+func (this *Builder) DropIfExists(table string) error {
+	bp := this.createBlueprint(table)
+	bp.DropIfExists()
+	return this.Build(bp)
+}
+
+func (b *Builder) createBlueprint(table string) *Blueprint {
+	return NewBlueprint(table)
+}
+
+// Build execute the blueprint to build / modify the table
+func (this *Builder) Build(bp *Blueprint) error {
+	return bp.Build(this.Connection, this.Grammar)
+}