feature: support different case style for different format

README.md

@@ -644,6 +644,28 @@ down_singular = "teamName"
   foreign = "Videos"
 ```
 
+
+##### Custom Struct Tag Case
+
+Sometimes you might want to customize the case style for different purpose, for example, use camel case for json format and use snake case for yaml,
+You may create a section named `[struct-tag-cases]` to define these custom case for each different format:
+
+```toml
+[struct-tag-cases]
+toml = "snake"
+yaml = "camel"
+json = "camel"
+boil = "alias"
+```
+
+By default, the snake case will be used, so you can just setup only few formats:
+
+```toml
+[struct-tag-cases]
+json = "camel"
+```
+
+
 ##### Foreign Keys
 
 You can add foreign keys not defined in the database to your models using the following configuration:

boilingcore/boilingcore.go

@@ -149,6 +149,7 @@ func (s *State) Run() error {
 		NoBackReferencing: s.Config.NoBackReferencing,
 		AlwaysWrapErrors:  s.Config.AlwaysWrapErrors,
 		StructTagCasing:   s.Config.StructTagCasing,
+		StructTagCases:    s.Config.StructTagCases,
 		TagIgnore:         make(map[string]struct{}),
 		Tags:              s.Config.Tags,
 		RelationTag:       s.Config.RelationTag,

boilingcore/config.go

@@ -14,6 +14,15 @@ import (
 	"github.com/volatiletech/sqlboiler/v4/importers"
 )
 
+type TagCase string
+
+const (
+	TagCaseCamel TagCase = "camel"
+	TagCaseSnake TagCase = "snake"
+	TagCaseTitle TagCase = "title"
+	TagCaseAlias TagCase = "alias"
+)
+
 // Config for the running of the commands
 type Config struct {
 	DriverName   string         `toml:"driver_name,omitempty" json:"driver_name,omitempty"`
@@ -39,9 +48,16 @@ type Config struct {
 	NoBackReferencing bool     `toml:"no_back_reference,omitempty" json:"no_back_reference,omitempty"`
 	AlwaysWrapErrors  bool     `toml:"always_wrap_errors,omitempty" json:"always_wrap_errors,omitempty"`
 	Wipe              bool     `toml:"wipe,omitempty" json:"wipe,omitempty"`
-	StructTagCasing   string   `toml:"struct_tag_casing,omitempty" json:"struct_tag_casing,omitempty"`
-	RelationTag       string   `toml:"relation_tag,omitempty" json:"relation_tag,omitempty"`
-	TagIgnore         []string `toml:"tag_ignore,omitempty" json:"tag_ignore,omitempty"`
+
+	StructTagCases StructTagCases `toml:"struct_tag_cases,omitempty" json:"struct_tag_cases,omitempty"`
+
+	// StructTagCasing is a legacy config field, which will be migrated to StructTagCases in the future.
+	// When struct-tag-casing is defined, it will be converted to StructTagCases
+	// Deprecated: use StructTagCases instead.
+	StructTagCasing string `toml:"struct_tag_casing,omitempty" json:"struct_tag_casing,omitempty"`
+
+	RelationTag string   `toml:"relation_tag,omitempty" json:"relation_tag,omitempty"`
+	TagIgnore   []string `toml:"tag_ignore,omitempty" json:"tag_ignore,omitempty"`
 
 	Imports importers.Collection `toml:"imports,omitempty" json:"imports,omitempty"`
 
@@ -63,6 +79,13 @@ type AutoColumns struct {
 	Deleted string `toml:"deleted,omitempty" json:"deleted,omitempty"`
 }
 
+type StructTagCases struct {
+	Json TagCase `toml:"json,omitempty" json:"json,omitempty"`
+	Yaml TagCase `toml:"yaml,omitempty" json:"yaml,omitempty"`
+	Toml TagCase `toml:"toml,omitempty" json:"toml,omitempty"`
+	Boil TagCase `toml:"boil,omitempty" json:"boil,omitempty"`
+}
+
 // TypeReplace replaces a column type with something else
 type TypeReplace struct {
 	Tables  []string       `toml:"tables,omitempty" json:"tables,omitempty"`

boilingcore/templates.go

@@ -14,8 +14,9 @@ import (
 
 	"github.com/Masterminds/sprig/v3"
 	"github.com/friendsofgo/errors"
-	"github.com/volatiletech/sqlboiler/v4/drivers"
 	"github.com/volatiletech/strmangle"
+
+	"github.com/volatiletech/sqlboiler/v4/drivers"
 )
 
 // templateData for sqlboiler templates
@@ -58,8 +59,12 @@ type templateData struct {
 	RelationTag string
 
 	// Generate struct tags as camelCase or snake_case
+	// Deprecated: use StructTagCases instead.
 	StructTagCasing string
 
+	// Generate struct tags as camelCase or snake_case
+	StructTagCases StructTagCases
+
 	// Contains field names that should have tags values set to '-'
 	TagIgnore map[string]struct{}
 
@@ -133,7 +138,9 @@ func (t templateList) Templates() []string {
 	return ret
 }
 
-func loadTemplates(lazyTemplates []lazyTemplate, testTemplates bool, customFuncs template.FuncMap) (*templateList, error) {
+func loadTemplates(
+	lazyTemplates []lazyTemplate, testTemplates bool, customFuncs template.FuncMap,
+) (*templateList, error) {
 	tpl := template.New("")
 
 	for _, t := range lazyTemplates {
@@ -286,13 +293,14 @@ var templateFunctions = template.FuncMap{
 	"ignore":    strmangle.Ignore,
 
 	// String Slice ops
-	"join":               func(sep string, slice []string) string { return strings.Join(slice, sep) },
-	"joinSlices":         strmangle.JoinSlices,
-	"stringMap":          strmangle.StringMap,
-	"prefixStringSlice":  strmangle.PrefixStringSlice,
-	"containsAny":        strmangle.ContainsAny,
-	"generateTags":       strmangle.GenerateTags,
-	"generateIgnoreTags": strmangle.GenerateIgnoreTags,
+	"join":                func(sep string, slice []string) string { return strings.Join(slice, sep) },
+	"joinSlices":          strmangle.JoinSlices,
+	"stringMap":           strmangle.StringMap,
+	"prefixStringSlice":   strmangle.PrefixStringSlice,
+	"containsAny":         strmangle.ContainsAny,
+	"generateTags":        strmangle.GenerateTags,
+	"generateTagWithCase": generateTagWithCase,
+	"generateIgnoreTags":  strmangle.GenerateIgnoreTags,
 
 	// Enum ops
 	"parseEnumName": strmangle.ParseEnumName,
@@ -333,3 +341,32 @@ var templateFunctions = template.FuncMap{
 	"columnDBTypes":          drivers.ColumnDBTypes,
 	"getTable":               drivers.GetTable,
 }
+
+func generateTagWithCase(tagName, tagValue, alias string, c TagCase, nullable bool) string {
+	buf := strmangle.GetBuffer()
+	defer strmangle.PutBuffer(buf)
+
+	buf.WriteString(tagName)
+	buf.WriteString(`:"`)
+	switch c {
+	case TagCaseSnake:
+		// we use snake case by default, so we can simply render the value to the buffer
+		buf.WriteString(tagValue)
+	case TagCaseTitle:
+		buf.WriteString(strmangle.TitleCase(tagValue))
+	case TagCaseCamel:
+		buf.WriteString(strmangle.CamelCase(tagValue))
+	case TagCaseAlias:
+		buf.WriteString(alias)
+	default:
+		buf.WriteString(tagValue)
+	}
+
+	if nullable {
+		buf.WriteString(",omitempty")
+	}
+
+	buf.WriteString(`" `)
+
+	return buf.String()
+}

main.go

@@ -172,13 +172,20 @@ func preRun(cmd *cobra.Command, args []string) error {
 		AlwaysWrapErrors:  viper.GetBool("always-wrap-errors"),
 		Wipe:              viper.GetBool("wipe"),
 		StructTagCasing:   strings.ToLower(viper.GetString("struct-tag-casing")), // camel | snake | title
-		TagIgnore:         viper.GetStringSlice("tag-ignore"),
-		RelationTag:       viper.GetString("relation-tag"),
-		TemplateDirs:      viper.GetStringSlice("templates"),
-		Tags:              viper.GetStringSlice("tag"),
-		Replacements:      viper.GetStringSlice("replace"),
-		Aliases:           boilingcore.ConvertAliases(viper.Get("aliases")),
-		TypeReplaces:      boilingcore.ConvertTypeReplace(viper.Get("types")),
+		StructTagCases: boilingcore.StructTagCases{
+			// make this compatible with the legacy struct-tag-casing config
+			Json: withDefaultCase(viper.GetString("struct-tag-cases.json"), viper.GetString("struct-tag-casing")),
+			Yaml: withDefaultCase(viper.GetString("struct-tag-cases.yaml"), viper.GetString("struct-tag-casing")),
+			Toml: withDefaultCase(viper.GetString("struct-tag-cases.toml"), viper.GetString("struct-tag-casing")),
+			Boil: withDefaultCase(viper.GetString("struct-tag-cases.boil"), viper.GetString("struct-tag-casing")),
+		},
+		TagIgnore:    viper.GetStringSlice("tag-ignore"),
+		RelationTag:  viper.GetString("relation-tag"),
+		TemplateDirs: viper.GetStringSlice("templates"),
+		Tags:         viper.GetStringSlice("tag"),
+		Replacements: viper.GetStringSlice("replace"),
+		Aliases:      boilingcore.ConvertAliases(viper.Get("aliases")),
+		TypeReplaces: boilingcore.ConvertTypeReplace(viper.Get("types")),
 		AutoColumns: boilingcore.AutoColumns{
 			Created: viper.GetString("auto-columns.created"),
 			Updated: viper.GetString("auto-columns.updated"),
@@ -293,3 +300,17 @@ func allKeys(prefix string) []string {
 	}
 	return keySlice
 }
+
+func withDefaultCase(configCase string, defaultCases ...string) boilingcore.TagCase {
+	if len(configCase) > 0 {
+		return boilingcore.TagCase(strings.ToLower(configCase))
+	}
+
+	for _, c := range defaultCases {
+		if len(c) > 0 {
+			return boilingcore.TagCase(strings.ToLower(c))
+		}
+	}
+
+	return boilingcore.TagCaseSnake
+}

templates/main/00_struct.go.tpl

@@ -8,18 +8,38 @@ type {{$alias.UpSingular}} struct {
 	{{- $orig_col_name := $column.Name -}}
 	{{- range $column.Comment | splitLines -}} // {{ . }}
 	{{end -}}
+
 	{{if ignore $orig_tbl_name $orig_col_name $.TagIgnore -}}
 	{{$colAlias}} {{$column.Type}} `{{generateIgnoreTags $.Tags}}boil:"{{$column.Name}}" json:"-" toml:"-" yaml:"-"`
-	{{else if eq $.StructTagCasing "title" -}}
-	{{$colAlias}} {{$column.Type}} `{{generateTags $.Tags $column.Name}}boil:"{{$column.Name}}" json:"{{$column.Name | titleCase}}{{if $column.Nullable}},omitempty{{end}}" toml:"{{$column.Name | titleCase}}" yaml:"{{$column.Name | titleCase}}{{if $column.Nullable}},omitempty{{end}}"`
-	{{else if eq $.StructTagCasing "camel" -}}
-	{{$colAlias}} {{$column.Type}} `{{generateTags $.Tags $column.Name}}boil:"{{$column.Name}}" json:"{{$column.Name | camelCase}}{{if $column.Nullable}},omitempty{{end}}" toml:"{{$column.Name | camelCase}}" yaml:"{{$column.Name | camelCase}}{{if $column.Nullable}},omitempty{{end}}"`
-	{{else if eq $.StructTagCasing "alias" -}}
-	{{$colAlias}} {{$column.Type}} `{{generateTags $.Tags $colAlias}}boil:"{{$column.Name}}" json:"{{$colAlias}}{{if $column.Nullable}},omitempty{{end}}" toml:"{{$colAlias}}" yaml:"{{$colAlias}}{{if $column.Nullable}},omitempty{{end}}"`
-	{{else -}}
-	{{$colAlias}} {{$column.Type}} `{{generateTags $.Tags $column.Name}}boil:"{{$column.Name}}" json:"{{$column.Name}}{{if $column.Nullable}},omitempty{{end}}" toml:"{{$column.Name}}" yaml:"{{$column.Name}}{{if $column.Nullable}},omitempty{{end}}"`
-	{{end -}}
-	{{end -}}
+	{{- else -}}
+
+	{{- /* render column alias and column type */ -}}
+	{{ $colAlias }} {{ $column.Type -}}
+
+	{{- /*
+	  handle struct tags
+	  StructTagCasing will be replaced with $.StructTagCases
+	  however we need to keep this backward compatible
+	  $.StructTagCasing will only be used when it's set to "alias"
+    */ -}}
+	`
+	{{- if eq $.StructTagCasing "alias" -}}
+	    {{- generateTags $.Tags $colAlias -}}
+	    {{- generateTagWithCase "json" $column.Name $colAlias "alias" $column.Nullable -}}
+	    {{- generateTagWithCase "yaml" $column.Name $colAlias "alias" $column.Nullable -}}
+	    {{- generateTagWithCase "toml" $column.Name $colAlias "alias" $column.Nullable -}}
+	    {{- generateTagWithCase "boil" $column.Name $colAlias "alias" $column.Nullable -}}
+	{{- else -}}
+	    {{- generateTags $.Tags $column.Name }}
+	    {{- generateTagWithCase "json" $column.Name $colAlias $.StructTagCases.Json $column.Nullable -}}
+	    {{- generateTagWithCase "yaml" $column.Name $colAlias $.StructTagCases.Yaml $column.Nullable -}}
+	    {{- generateTagWithCase "toml" $column.Name $colAlias $.StructTagCases.Toml $column.Nullable -}}
+	    {{- generateTagWithCase "boil" $column.Name $colAlias $.StructTagCases.Boil $column.Nullable -}}
+	{{- end -}}
+	`
+	{{ end -}}
+	{{ end -}}
+
 	{{- if or .Table.IsJoinTable .Table.IsView -}}
 	{{- else}}
 	R *{{$alias.DownSingular}}R `{{generateTags $.Tags $.RelationTag}}boil:"{{$.RelationTag}}" json:"{{$.RelationTag}}" toml:"{{$.RelationTag}}" yaml:"{{$.RelationTag}}"`