英文:
Passing multiple values to expression.in() of aws-sdk-go-v2 for DynamoDB
问题
我正在尝试将一个值列表传递给aws-sdk-go-v2中的'IN'表达式，但我无法弄清楚如何以动态方式实现。
以下是当前的代码示例：
func Find(colors []string) ([]Trip, error) {
db := database.GetClient()
filt := expression.In(
expression.Name("color"),
expression.Value(colors[0]),
expression.Value(colors[1]),
)
expr, err := expression.NewBuilder().WithFilter(filt).Build()
if err != nil {
fmt.Println(err)
}
params := &dynamodb.ScanInput{
ExpressionAttributeNames: expr.Names(),
ExpressionAttributeValues: expr.Values(),
FilterExpression: expr.Filter(),
TableName: aws.String("Test"),
}
resp, err := db.Scan(context.TODO(), params)
}
我想要使列表值动态化，而不是通过索引访问。像下面这样：
filt := expression.In(expression.Name("color"), expression.Value(colors))
我该如何实现这个目标？
英文:
I am trying to pass a list of values to the 'IN' expression in aws-sdk-go-v2 and I cannot figure out how to do it dynamically.
This is what it looks like now.
func Find(colors []string) ([]Trip, error) {
db := database.GetClient()
filt := expression.In(
expression.Name("color"),
expression.Value(colors[0]),
expression.Value(colors[1]),
)
expr, err := expression.NewBuilder().WithFilter(filt).Build()
if err != nil {
fmt.Println(err)
}
params := &dynamodb.ScanInput{
ExpressionAttributeNames: expr.Names(),
ExpressionAttributeValues: expr.Values(),
FilterExpression: expr.Filter(),
TableName: aws.String("Test"),
}
resp, err := db.Scan(context.TODO(), params)
}
I'd like to make the list values dynamic without accessing using their index. Like below,
filt := expression.In(expression.Name("color"),expression.Value(colors))
How can I achieve this?
答案1
得分: 1
请稍等，我会为您翻译以下内容：
参见将参数传递给...参数在语言规范中。
package main
import (
"fmt";
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
)
func main() {
colors := []string{"red", "blue", "green"}
if len(colors) == 0 {
panic("colors should not be empty")
}
values := make([]expression.OperandBuilder, len(colors))
for i, c := range colors {
values[i] = expression.Value(c)
}
filter := expression.In(
expression.Name("color"),
values[0],
values[1:]...,
)
fmt.Println(filter)
}
英文:
See Passing arguments to ... parameters in the language spec.
package main
import (
"fmt"
"github.com/aws/aws-sdk-go-v2/feature/dynamodb/expression"
)
func main() {
colors := []string{"red", "blue", "green"}
if len(colors) == 0 {
panic("colors should not be empty")
}
values := make([]expression.OperandBuilder, len(colors))
for i, c := range colors {
values[i] = expression.Value(c)
}
filter := expression.In(
expression.Name("color"),
values[0],
values[1:]...,
)
fmt.Println(filter)
}
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