golang Couchbase n1ql 查询将参数传递给?

golang Couchbase n1ql query pass params to?

我正在尝试寻找一种方法来将参数传递给查询,但不太确定如何。 web site 上的 API 看起来有点过时了?

myQuery := gocb.NewN1qlQuery("SELECT * FROM default")
rows, err := myBucket.ExecuteN1qlQuery(myQuery)
if err != nil {
    fmt.Printf("N1QL query error: %s\n", err)
}
var row interface{}
for rows.Next(&row) {
    fmt.Printf("Row: %+v\n", row)
}
if err := rows.Close(); err != nil {
    fmt.Printf("N1QL query error: %s\n", err)
}

因为,实际上 ExecuteN1qlQuery 有两个参数:

func (b *Bucket) ExecuteN1qlQuery(q *N1qlQuery, params interface{}) (ViewResults, error)

我不确定如何使用它...就像我想创建一个带有占位符的查询,并通过参数将值传递给 ExecuteN1qlQuery。与 SQL 一样(准备 -> 执行)。例如:

    myQuery := gocb.NewN1qlQuery("SELECT * FROM default where a=? and b=?")
    rows, err := myBucket.ExecuteN1qlQuery(myQuery,[]string{"b","c"})
    if err != nil {
        fmt.Printf("N1QL query error: %s\n", err)
    }
    var row interface{}
    for rows.Next(&row) {
        fmt.Printf("Row: %+v\n", row)
    }
    if err := rows.Close(); err != nil {
        fmt.Printf("N1QL query error: %s\n", err)
    }

刚刚found example

        myQuery := gocb.NewN1qlQuery("SELECT airportname, city, country FROM `travel-sample` " +
        "WHERE type='airport' AND city= ")

    // Setup an array for parameters
    var myParams []interface{}
    myParams = append(myParams, "Reno")

    // Execute Query
    rows, err := bucket.ExecuteN1qlQuery(myQuery, myParams)

您发布的有关如何执行此操作的示例来自我们在 github 上的开发人员指南存储库:

https://github.com/couchbaselabs/devguide-examples/blob/master/go/query-placeholders.go.

基本上,您使用的是引用接口和以 1 开头的相应位置参数的 $。

对于您的示例,它看起来像:

// Setup a new query with a placeholder
myQuery := gocb.NewN1qlQuery("SELECT * FROM default where a= and b=")

// Setup an array for parameters
var myParams []interface{}
myParams = append(myParams,"foo")
myParams = append(myParams,"bar")

// Execute Query
rows, err := bucket.ExecuteN1qlQuery(myQuery, myParams)
if err != nil {
    fmt.Println("ERROR EXECUTING N1QL QUERY:", err)
}

// Iterate through rows and print output
var row interface{}
for rows.Next(&row) {
    fmt.Printf("Results: %+v\n", row)
}