1. 实现配置文件解析

2. 实现数据库连接

vendor/gorm.io/gorm/schema/constraint.go

@@ -0,0 +1,66 @@
+package schema
+
+import (
+	"regexp"
+	"strings"
+
+	"gorm.io/gorm/clause"
+)
+
+// reg match english letters and midline
+var regEnLetterAndMidline = regexp.MustCompile("^[A-Za-z-_]+$")
+
+type CheckConstraint struct {
+	Name       string
+	Constraint string // length(phone) >= 10
+	*Field
+}
+
+func (chk *CheckConstraint) GetName() string { return chk.Name }
+
+func (chk *CheckConstraint) Build() (sql string, vars []interface{}) {
+	return "CONSTRAINT ? CHECK (?)", []interface{}{clause.Column{Name: chk.Name}, clause.Expr{SQL: chk.Constraint}}
+}
+
+// ParseCheckConstraints parse schema check constraints
+func (schema *Schema) ParseCheckConstraints() map[string]CheckConstraint {
+	checks := map[string]CheckConstraint{}
+	for _, field := range schema.FieldsByDBName {
+		if chk := field.TagSettings["CHECK"]; chk != "" {
+			names := strings.Split(chk, ",")
+			if len(names) > 1 && regEnLetterAndMidline.MatchString(names[0]) {
+				checks[names[0]] = CheckConstraint{Name: names[0], Constraint: strings.Join(names[1:], ","), Field: field}
+			} else {
+				if names[0] == "" {
+					chk = strings.Join(names[1:], ",")
+				}
+				name := schema.namer.CheckerName(schema.Table, field.DBName)
+				checks[name] = CheckConstraint{Name: name, Constraint: chk, Field: field}
+			}
+		}
+	}
+	return checks
+}
+
+type UniqueConstraint struct {
+	Name  string
+	Field *Field
+}
+
+func (uni *UniqueConstraint) GetName() string { return uni.Name }
+
+func (uni *UniqueConstraint) Build() (sql string, vars []interface{}) {
+	return "CONSTRAINT ? UNIQUE (?)", []interface{}{clause.Column{Name: uni.Name}, clause.Column{Name: uni.Field.DBName}}
+}
+
+// ParseUniqueConstraints parse schema unique constraints
+func (schema *Schema) ParseUniqueConstraints() map[string]UniqueConstraint {
+	uniques := make(map[string]UniqueConstraint)
+	for _, field := range schema.Fields {
+		if field.Unique {
+			name := schema.namer.UniqueName(schema.Table, field.DBName)
+			uniques[name] = UniqueConstraint{Name: name, Field: field}
+		}
+	}
+	return uniques
+}