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Tri Dao 2024-11-14 19:00:21 +08:00 committed by GitHub
commit f6fba9d167
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2 changed files with 114 additions and 0 deletions

54
clause/expr_case.go Normal file
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package clause
type ExprCaseCondition struct {
When string
Then string
Vars []any
}
type ExprCaseElse struct {
Then string
Vars []any
}
type ExprCase struct {
Cases []*ExprCaseCondition
Else *ExprCaseElse
}
func (expr ExprCase) Name() string {
return "CASE"
}
func (expr ExprCase) Build(builder Builder) {
var vars []any
for idx, condition := range expr.Cases {
if idx > 0 {
_ = builder.WriteByte(' ')
}
_, _ = builder.WriteString("WHEN ")
_, _ = builder.WriteString(condition.When)
_, _ = builder.WriteString(" THEN ")
_, _ = builder.WriteString(condition.Then)
if len(condition.Vars) > 0 {
vars = append(vars, condition.Vars...)
}
}
if expr.Else != nil {
elseExpr := expr.Else
_, _ = builder.WriteString(" ELSE ")
_, _ = builder.WriteString(elseExpr.Then)
if len(elseExpr.Vars) > 0 {
vars = append(vars, elseExpr.Vars...)
}
}
_, _ = builder.WriteString(" END")
clauseExpr := Expr{SQL: "", Vars: vars}
clauseExpr.Build(builder)
}
func (expr ExprCase) MergeClause(clause *Clause) {
clause.Expression = expr
}

60
clause/expr_case_test.go Normal file
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package clause_test
import (
"testing"
"gorm.io/gorm"
"gorm.io/gorm/clause"
)
func Test_ExprCase(t *testing.T) {
type exampleUser struct {
ID string
Name string
}
inputUsers := []*exampleUser{
{
ID: "user-001",
Name: "user-name-001",
},
{
ID: "user-002",
Name: "user-name-002",
},
}
userIDs := make([]string, len(inputUsers))
userNameCases := make([]*clause.ExprCaseCondition, len(inputUsers))
for idx, user := range inputUsers {
userIDs[idx] = user.ID
userNameCases[idx] = &clause.ExprCaseCondition{
When: "user_id=?",
Then: "?",
Vars: []any{
user.ID,
user.Name,
},
}
}
sqlQuery := db.ToSQL(func(db *gorm.DB) *gorm.DB {
return db.
Table("users").
Where("user_id IN (?)", userIDs).
UpdateColumns(map[string]any{
"user_name": clause.ExprCase{
Cases: userNameCases,
Else: &clause.ExprCaseElse{
Then: "user_name",
Vars: nil,
},
},
})
})
expectedSQLQuery := "UPDATE `users` SET `user_name`=CASE WHEN user_id=\"user-001\" THEN \"user-name-001\" WHEN user_id=\"user-002\" THEN \"user-name-002\" ELSE user_name END WHERE user_id IN (\"user-001\",\"user-002\")"
if sqlQuery != expectedSQLQuery {
t.Errorf("SQLQuery is mismatch actual: %v expected:%v\n", sqlQuery, expectedSQLQuery)
}
}