Postgresql 如何正确分组Postgres数据
在PostgreSQL中,我有这样的表:Postgresql 如何正确分组Postgres数据,postgresql,go,go-gorm,Postgresql,Go,Go Gorm,在PostgreSQL中,我有这样的表: |问题|文本|类别|同意|百分比|不同意|百分比| |----------------------------------------|----------|---------------|------------------| |你支持总统的政策吗政策| 50 | 50| |你支持民主党吗政策| 32 | 68| |你支持兰尼斯特一家吗电影院| 45 | 55| |你支持斯皮尔伯格的工作吗电影院| 60 | 40| 在我的Go应用程序中,在的帮助下,
|问题|文本|类别|同意|百分比|不同意|百分比|
|----------------------------------------|----------|---------------|------------------|
|你支持总统的政策吗政策| 50 | 50|
|你支持民主党吗政策| 32 | 68|
|你支持兰尼斯特一家吗电影院| 45 | 55|
|你支持斯皮尔伯格的工作吗电影院| 60 | 40|
在我的Go应用程序中,在的帮助下,我向PostgreSQL数据库发出如下SQL请求:
type Entry struct {
QuestionText string `json:"question_text"`
Category string `json:"category"`
AgreePercent float64 `json:"agree_percent"`
DisagreePercent float64 `json:"disagree_percent"`
}
rows, _ := database.DBGORM.Raw("SELECT * FROM SPECIFICATION").Rows()
for rows.Next() {
entry := &Entry{}
if err = rows.Scan(&entry.QuestionText, & entry.Category, &entry.AgreePercent, &entry.DisagreePercent); err != nil {
utils.Logger().Println(err)
}
}
如何得到类似的结果?如您所见,数组中的每个对象都按类别
列中的值分组:
[
{
category: "Policy",
questions: ["Do you support the President's policy?", "Do you support Democrats?"],
series: [
{
name: "Agree, %",
data: [50, 32]
},
{
name: "Disagree, %",
data: [50, 68]
},
]
},
{
category: "Cinema",
questions: ["Do you support the Lannisters?", "Do you support Spielberg's work?"],
series: [
{
name: "Agree, %",
data: [45, 60]
},
{
name: "Disagree, %",
data: [55, 40]
},
]
},
]
嗯,我不能说这是一种优雅的方式,但最终我解决了我的任务:
// Create struct called "Series".
type Series struct {
Name string `json:"name"`
Data []float64 `json:"data"`
}
// Create struct called "Specification".
type Specification struct {
Category string `json:"category"`
Questions []string `json:"questions"`
Series []Series `json:"series"`
}
// Initialize an array of struct.
var specifications []Specification
// Initialize several variables.
var catogoryName string
var arrayQuestionText []string
var arrayAgreePercent []float64
var arrayDisagreePercent []float64
for rows.Next() {
// Check the change in the name of the category.
if entry.Category == catogoryName {
// Add new elements to arrays.
arrayQuestionText = append(arrayQuestionText, entry.QuestionText)
arrayDisagreePercent = append(arrayDisagreePercent, entry.DisagreePercent)
arrayAgreePercent = append(arrayAgreePercent, entry.AgreePercent)
} else {
if len(catogoryName) > 0 {
// Fill the struct with data.
specification := Specification{
Category: catogoryName,
Questions: arrayQuestionText,
Series: []Series{
{
Name: "Agree, %",
Data: arrayAgreePercent,
},
{
Name: "Disagree, %",
Data: arrayDisagreePercent,
},
},
}
// Add new struct to array.
specifications = append(specifications, specification)
}
}
// Update data in arrays.
catogoryName = entry.Category
arrayQuestionText = nil
arrayQuestionText = append(arrayQuestionText, entry.QuestionText)
arrayDisagreePercent = nil
arrayDisagreePercent = append(arrayDisagreePercent, entry.DisagreePercent)
arrayAgreePercent = nil
arrayAgreePercent = append(arrayAgreePercent, entry.AgreePercent)
}
最后一个片段是您想要得到的还是您实际得到的?“如何获得类似的结果?”–类似于什么?您没有显示此输出是从何处生成的,因此很难知道分组的作用是什么。我的猜测是,稍后会有一些逻辑进行分组,并打印分组后的输出。如果在从数据库读取扫描行时打印出每一行,则应看到pg的原始近似值table@EliBendersky目前没有分组。我想要上面例子中的输出。你知道我怎么做吗?@mkrieger1你好!在文章的最后,您可以注意到我希望在golang应用程序中生成的JSON输出。如何得到这样的结果?你有什么想法吗?