Hi, I am very new with go and I don't know how to access the values

Hi <a class="user-mention notranslate" data-hovercard-type="user" data-hovercard-url="

Finally I found the problem <a class="user-mention notranslate" data-hovercard-type="u

How to access header values with the Push api ?,about thmeitz/ksqldb-go

thmeitz commented on June 18, 2024

Hi @fenix01,

forget my previous answer, I was wrong.

ksqldb-go/types.go

Lines 90 to 93 in 895ad65

    
           type Header struct { 
        
           	QueryId string   `json:"queryId"` 
        
           	Columns []Column `json:"Columns"` 
        
           }

The Header contains Colum Data

ksqldb-go/types.go

Lines 96 to 99 in 895ad65

    
           type Column struct { 
        
           	Name string 
        
           	Type string 
        
           }

fmt.Printf("%s\n",header.QueryId)

Here is the code how the header processing is working:

ksqldb-go/pull.go

Lines 115 to 132 in 895ad65

    
           func processHeader(data map[string]interface{}) (header Header) { 
        
           	if _, ok := data["queryId"].(string); ok { 
        
           		header.QueryId = data["queryId"].(string) 
        
           	} 
        
           	names, okNames := data["columnNames"].([]interface{}) 
        
           	types, okTypes := data["columnTypes"].([]interface{}) 
        
           	if okNames && okTypes { 
        
           		for col := range names { 
        
           			if colName, ok := names[col].(string); colName != "" && ok { 
        
           				if colType, ok := types[col].(string); colType != "" && ok { 
        
           					header.Columns = append(header.Columns, Column{Name: colName, Type: colType}) 
        
           				} 
        
           			} 
        
           		} 
        
           	} 
        
           	return 
        
           }

from ksqldb-go.

fenix01 commented on June 18, 2024

Hi @thmeitz !
Thank you for your response. I tried to understand your current message and the first one. But I don't understand how I can access the column name with the headerChannel variable.
If I understand correctly you say that I should not be able to read from the header channel while processing the row channel. But my printf function is able to display the header from the row channel. But I cannot access the Columns field, neither its QueryId field.
I would like to parse a row and know what is the corresponding column name. But it doesn't work.

from ksqldb-go.

fenix01 commented on June 18, 2024

Finally I found the problem @thmeitz !
I was using ksqldb-go in version v0.0.4 because it is the latest version in the release page. But in this version the Header struct is written like this.

ksqldb-go/types.go

Lines 113 to 116 in 7babf9f

    
           type Header struct { 
        
           	queryId string 
        
           	columns []Column 
        
           }

As you can see, all fields are in lowercase and are not exposed to the outside. So I cannot access columns field from my code.
It has been changed in the master branch :

ksqldb-go/types.go

Lines 90 to 93 in 895ad65

    
           type Header struct { 
        
           	QueryId string   `json:"queryId"` 
        
           	Columns []Column `json:"Columns"` 
        
           }

I added the library by pointing to the latest commit and now it works correctly.

go get github.com/thmeitz/ksqldb-go@895ad659e4025274b4d4ddbaae941903525f078a

from ksqldb-go.

How to access header values with the Push api ? about ksqldb-go HOT 3 CLOSED

Comments (3)

Related Issues (19)

Recommend Projects

React

Vue.js

Typescript

TensorFlow

Django

Laravel

D3

Recommend Topics

javascript

web

server

Machine learning

Visualization

Game

Recommend Org

Facebook

Microsoft

Google

Alibaba

D3

Tencent

	type Header struct {
	QueryId string `json:"queryId"`
	Columns []Column `json:"Columns"`
	}

	func processHeader(data map[string]interface{}) (header Header) {
	if _, ok := data["queryId"].(string); ok {
	header.QueryId = data["queryId"].(string)
	}

	names, okNames := data["columnNames"].([]interface{})
	types, okTypes := data["columnTypes"].([]interface{})
	if okNames && okTypes {
	for col := range names {
	if colName, ok := names[col].(string); colName != "" && ok {
	if colType, ok := types[col].(string); colType != "" && ok {
	header.Columns = append(header.Columns, Column{Name: colName, Type: colType})
	}
	}
	}
	}
	return
	}