StructFieldNamer returns FieldFlag bitmask, don't write columns with FieldFlagReadOnly

ungerik · ungerik · commit a32d5e157f73 · 2021-03-09T21:26:51.000+01:00
diff --git a/cmd/gen-db-interface/go.mod b/cmd/gen-db-interface/go.mod
@@ -1,9 +1,10 @@
 module github.com/domonda/go-sqldb/cmd/gen-db-interface
 
-go 1.14
+go 1.16
 
 require (
 	github.com/ungerik/go-astvisit v0.0.0-20191030134654-e9cef48dc381
 	github.com/ungerik/go-fs v0.0.0-20210217101829-a7a4ab03e83c
 	github.com/vburenin/ifacemaker v1.1.0
+	golang.org/x/tools v0.1.0 // indirect
 )
diff --git a/cmd/gen-db-interface/go.sum b/cmd/gen-db-interface/go.sum
@@ -21,18 +21,34 @@ github.com/ungerik/go-fs v0.0.0-20210217101829-a7a4ab03e83c h1:DVh4+JUlHqS4UwPAD
 github.com/ungerik/go-fs v0.0.0-20210217101829-a7a4ab03e83c/go.mod h1:GLCikCNg1ILlfLTS6ZmYc1m9gnPiCffruY8rawwjzEA=
 github.com/vburenin/ifacemaker v1.1.0 h1:3ScCGZ+D65Ud9L0x9ofhN0dk5QrfauzMWYfaYsfA+HE=
 github.com/vburenin/ifacemaker v1.1.0/go.mod h1:SlS6qpTccQsoK3ln7mBkUxA4agA8wfPr/IFYqBWerPw=
+github.com/yuin/goldmark v1.2.1/go.mod h1:3hX8gzYuyVAZsxl0MRgGTJEmQBFcNTphYh9decYSb74=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/mod v0.3.0 h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
+golang.org/x/mod v0.3.0/go.mod h1:s0Qsj1ACt9ePp/hMypM3fl4fZqREWJwdYDEqhRiZZUA=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
 golang.org/x/net v0.0.0-20201110031124-69a78807bb2b/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20201020160332-67f06af15bc9/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 h1:myAQVi0cGEoqQVR5POX+8RR2mrocKqNN1hmeMqhX27k=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
-golang.org/x/tools v0.0.0-20181201035826-d0ca3933b724 h1:eV9myT/I6o1p8salzgZ0f1pz54PEgUf2NkCxEf6t+xs=
 golang.org/x/tools v0.0.0-20181201035826-d0ca3933b724/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.0 h1:po9/4sTYwZU9lPhi1tOrb4hCv3qrhiQ77LZfGa2OjwY=
+golang.org/x/tools v0.1.0/go.mod h1:xkSsbof2nBLbhDlRMhhhyNLN/zl3eTqcnHD5viDpcZ0=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/cmd/sqldb-dump/go.mod b/cmd/sqldb-dump/go.mod
@@ -1,10 +1,10 @@
 module github.com/domonda/go-sqldb/cmd/sqldb-dump
 
-go 1.14
+go 1.16
 
 require (
 	github.com/domonda/go-pretty v0.0.0-20210202131827-b4ff5dbd12fd
-	github.com/domonda/go-sqldb v0.0.0-20210209155119-b2b9cf662c4c
+	github.com/domonda/go-sqldb v0.0.0-20210218093113-4c92a0c9bd4f
 )
 
 replace github.com/domonda/go-sqldb => ../..
diff --git a/cmd/sqldb-dump/go.sum b/cmd/sqldb-dump/go.sum
@@ -48,6 +48,7 @@ github.com/domonda/go-types v0.0.0-20200708151211-d76e5982c26f/go.mod h1:cVAD1Oc
 github.com/domonda/go-types v0.0.0-20200812124141-0d4514dc5982/go.mod h1:cVAD1OcEuytU4/mE9gA+SbOQWLoSGLbAf/fdOgNBCeo=
 github.com/domonda/go-types v0.0.0-20200924083638-39ebc21394cd/go.mod h1:wz+6FtLIKMJf6AmWPqEvrts+/6Orehd2Q2PGSCgIhGA=
 github.com/domonda/go-types v0.0.0-20210205100405-94aad03cfa0e/go.mod h1:Gu8lMkGPGIrHeu4hhi8mDlmFecmtCgM+Dk1kuIuv6JI=
+github.com/domonda/go-types v0.0.0-20210308171246-14e42fd69187/go.mod h1:Gu8lMkGPGIrHeu4hhi8mDlmFecmtCgM+Dk1kuIuv6JI=
 github.com/domonda/go-wraperr v0.0.0-20191218095026-c132bf32bd96/go.mod h1:+StTOV14t8kZSKmDG8CfcXEBKTocUqZ9x8zuJHnXgII=
 github.com/domonda/go-wraperr v0.0.0-20200414143540-485fd6d06d5d/go.mod h1:+StTOV14t8kZSKmDG8CfcXEBKTocUqZ9x8zuJHnXgII=
 github.com/domonda/golog v0.0.0-20200104211507-b1ff3be34563/go.mod h1:35TUI0fS2sdkd11hmcqCoRrKEJIlWDaP54aROPpAxe8=
@@ -145,6 +146,7 @@ github.com/lib/pq v1.7.0 h1:h93mCPfUSkaul3Ka/VG8uZdmW1uMHDGxzu0NWHuJmHY=
 github.com/lib/pq v1.7.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/lib/pq v1.8.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/lib/pq v1.9.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/lib/pq v1.10.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/lucasb-eyer/go-colorful v1.0.3/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
diff --git a/go.mod b/go.mod
@@ -1,9 +1,9 @@
 module github.com/domonda/go-sqldb
 
-go 1.13
+go 1.16
 
 require (
-	github.com/domonda/go-types v0.0.0-20210205100405-94aad03cfa0e
-	github.com/lib/pq v1.9.0
+	github.com/domonda/go-types v0.0.0-20210308171246-14e42fd69187
+	github.com/lib/pq v1.10.0
 	github.com/stretchr/testify v1.7.0
 )
diff --git a/go.sum b/go.sum
@@ -37,8 +37,8 @@ github.com/domonda/go-types v0.0.0-20200617112812-98d67e39e1b2/go.mod h1:DzGRijk
 github.com/domonda/go-types v0.0.0-20200708151211-d76e5982c26f/go.mod h1:cVAD1OcEuytU4/mE9gA+SbOQWLoSGLbAf/fdOgNBCeo=
 github.com/domonda/go-types v0.0.0-20200812124141-0d4514dc5982/go.mod h1:cVAD1OcEuytU4/mE9gA+SbOQWLoSGLbAf/fdOgNBCeo=
 github.com/domonda/go-types v0.0.0-20200924083638-39ebc21394cd/go.mod h1:wz+6FtLIKMJf6AmWPqEvrts+/6Orehd2Q2PGSCgIhGA=
-github.com/domonda/go-types v0.0.0-20210205100405-94aad03cfa0e h1:MWL+EJVhTE+dAuEBBh4mH4aDXDomEaVGnQyJciExX7o=
-github.com/domonda/go-types v0.0.0-20210205100405-94aad03cfa0e/go.mod h1:Gu8lMkGPGIrHeu4hhi8mDlmFecmtCgM+Dk1kuIuv6JI=
+github.com/domonda/go-types v0.0.0-20210308171246-14e42fd69187 h1:U6VaIP6Pylvx9Z86Hxsn+CJrzP1emizRkuvP6cfmAjs=
+github.com/domonda/go-types v0.0.0-20210308171246-14e42fd69187/go.mod h1:Gu8lMkGPGIrHeu4hhi8mDlmFecmtCgM+Dk1kuIuv6JI=
 github.com/domonda/go-wraperr v0.0.0-20191218095026-c132bf32bd96/go.mod h1:+StTOV14t8kZSKmDG8CfcXEBKTocUqZ9x8zuJHnXgII=
 github.com/domonda/go-wraperr v0.0.0-20200414143540-485fd6d06d5d/go.mod h1:+StTOV14t8kZSKmDG8CfcXEBKTocUqZ9x8zuJHnXgII=
 github.com/domonda/golog v0.0.0-20200104211507-b1ff3be34563/go.mod h1:35TUI0fS2sdkd11hmcqCoRrKEJIlWDaP54aROPpAxe8=
@@ -130,8 +130,9 @@ github.com/labstack/gommon v0.3.0/go.mod h1:MULnywXg0yavhxWKc+lOruYdAhDwPK9wf0OL
 github.com/lib/pq v1.3.0/go.mod h1:5WUZQaWbwv1U+lTReE5YruASi9Al49XbQIvNi/34Woo=
 github.com/lib/pq v1.7.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/lib/pq v1.8.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
-github.com/lib/pq v1.9.0 h1:L8nSXQQzAYByakOFMTwpjRoHsMJklur4Gi59b6VivR8=
 github.com/lib/pq v1.9.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
+github.com/lib/pq v1.10.0 h1:Zx5DJFEYQXio93kgXnQ09fXNiUKsqv4OUEu2UtGcB1E=
+github.com/lib/pq v1.10.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
 github.com/lucasb-eyer/go-colorful v1.0.3/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
diff --git a/impl/insert.go b/impl/insert.go
@@ -134,7 +134,16 @@ func insertStructValues(table string, rowStruct interface{}, namer sqldb.StructF
 		return nil, nil, fmt.Errorf("InsertStruct into table %s: expected struct but got %T", table, rowStruct)
 	}
 
-	columns, _, vals = structFields(v, namer, ignoreColumns, restrictToColumns, false)
+	columns, flags, vals := structFields(v, namer, ignoreColumns, restrictToColumns, false)
+	for i := 0; i < len(columns); i++ {
+		// Remove readonly column data
+		if flags[i].IsReadOnly() {
+			columns = append(columns[:i], columns[i+1:]...)
+			flags = append(flags[:i], flags[i+1:]...)
+			vals = append(vals[:i], vals[i+1:]...)
+			i--
+		}
+	}
 	if len(columns) == 0 {
 		return nil, nil, fmt.Errorf("InsertStruct into table %s: %T has no exported struct fields with `db` tag", table, rowStruct)
 	}
diff --git a/impl/scanstruct.go b/impl/scanstruct.go
@@ -102,29 +102,29 @@ func getStructFieldPointers(v reflect.Value, namer sqldb.StructFieldNamer, ignor
 // the ,pk suffix in their struct field naming tag.
 // The same number of pkCol bools will be returend as names, every corresponding bool marking
 // if the name had the ,pk suffix in their struct field naming tag.
-func structFields(v reflect.Value, namer sqldb.StructFieldNamer, ignoreNames, restrictToNames []string, keepPK bool) (names []string, pkCol []bool, vals []interface{}) {
+func structFields(v reflect.Value, namer sqldb.StructFieldNamer, ignoreNames, restrictToNames []string, keepPK bool) (names []string, flags []sqldb.FieldFlag, vals []interface{}) {
 	for i := 0; i < v.NumField(); i++ {
 		field := v.Type().Field(i)
-		name, isPK, ok := namer.StructFieldName(field)
+		name, flag, ok := namer.StructFieldName(field)
 		if !ok {
 			continue
 		}
 
 		if field.Anonymous {
-			embedNames, embedPKs, embedValues := structFields(v.Field(i), namer, ignoreNames, restrictToNames, keepPK)
+			embedNames, embedFlags, embedValues := structFields(v.Field(i), namer, ignoreNames, restrictToNames, keepPK)
 			names = append(names, embedNames...)
-			pkCol = append(pkCol, embedPKs...)
+			flags = append(flags, embedFlags...)
 			vals = append(vals, embedValues...)
 			continue
 		}
 
-		if validName(name, ignoreNames, restrictToNames) || (isPK && keepPK && validName(name, nil, nil)) {
+		if validName(name, ignoreNames, restrictToNames) || (flag.IsPrimaryKey() && keepPK && validName(name, nil, nil)) {
 			names = append(names, name)
-			pkCol = append(pkCol, isPK)
+			flags = append(flags, flag)
 			vals = append(vals, v.Field(i).Interface())
 		}
 	}
-	return names, pkCol, vals
+	return names, flags, vals
 }
 
 // validName returns if a name not empty and not in ignoreNames
diff --git a/impl/update.go b/impl/update.go
@@ -76,7 +76,7 @@ func UpdateStruct(conn sqldb.Connection, table string, rowStruct interface{}, na
 		return fmt.Errorf("UpdateStruct of table %s: expected struct but got %T", table, rowStruct)
 	}
 
-	columns, pkCol, vals := structFields(v, namer, ignoreColumns, restrictToColumns, true)
+	columns, flags, vals := structFields(v, namer, ignoreColumns, restrictToColumns, true)
 	if len(columns) == 0 {
 		return fmt.Errorf("UpdateStruct of table %s: %T has no exported struct fields with `db` tag", table, rowStruct)
 	}
@@ -85,7 +85,7 @@ func UpdateStruct(conn sqldb.Connection, table string, rowStruct interface{}, na
 	fmt.Fprintf(&b, `UPDATE %s SET `, table)
 	first := true
 	for i := range columns {
-		if pkCol[i] {
+		if f := flags[i]; f.IsPrimaryKey() || f.IsReadOnly() {
 			continue
 		}
 		if first {
@@ -97,19 +97,19 @@ func UpdateStruct(conn sqldb.Connection, table string, rowStruct interface{}, na
 	}
 
 	b.WriteString(` WHERE `)
-	first = true
+	hasPK := false
 	for i := range columns {
-		if !pkCol[i] {
+		if !flags[i].IsPrimaryKey() {
 			continue
 		}
-		if first {
-			first = false
+		if !hasPK {
+			hasPK = true
 		} else {
 			b.WriteString(` AND `)
 		}
 		fmt.Fprintf(&b, `"%s"=$%d`, columns[i], i+1)
 	}
-	if first {
+	if !hasPK {
 		return fmt.Errorf("UpdateStruct of table %s: %T has no exported struct fields with ,pk tag value suffix to mark primary key column(s)", table, rowStruct)
 	}
 	query := b.String()
diff --git a/impl/upsert.go b/impl/upsert.go
@@ -26,34 +26,34 @@ func UpsertStruct(conn sqldb.Connection, table string, rowStruct interface{}, na
 		return fmt.Errorf("UpsertStruct to table %s: expected struct but got %T", table, rowStruct)
 	}
 
-	columns, pkCol, vals := structFields(v, namer, ignoreColumns, restrictToColumns, true)
+	columns, flags, vals := structFields(v, namer, ignoreColumns, restrictToColumns, true)
 	if len(columns) == 0 {
 		return fmt.Errorf("UpsertStruct to table %s: %T has no exported struct fields with `db` tag", table, rowStruct)
 	}
 
 	var b strings.Builder
 	writeInsertQuery(&b, table, columns)
 	b.WriteString(` ON CONFLICT(`)
-	first := true
+	hasPK := false
 	for i := range columns {
-		if !pkCol[i] {
+		if !flags[i].IsPrimaryKey() {
 			continue
 		}
-		if first {
-			first = false
+		if !hasPK {
+			hasPK = true
 		} else {
 			b.WriteByte(',')
 		}
 		fmt.Fprintf(&b, `"%s"`, columns[i])
 	}
-	if first {
+	if !hasPK {
 		return fmt.Errorf("UpsertStruct to table %s: %T has no exported struct fields with ,pk tag value suffix to mark primary key column(s)", table, rowStruct)
 	}
 
 	b.WriteString(`) DO UPDATE SET `)
-	first = true
+	first := true
 	for i := range columns {
-		if pkCol[i] {
+		if f := flags[i]; f.IsPrimaryKey() || f.IsReadOnly() {
 			continue
 		}
 		if first {
diff --git a/structfieldnamer.go b/structfieldnamer.go
@@ -7,13 +7,25 @@ import (
 	"unicode"
 )
 
+// FieldFlag is a bitmask for special properties
+// of how struct fields relate to database columns.
+type FieldFlag uint
+
+const (
+	FieldFlagPrimaryKey FieldFlag = 1 << iota
+	FieldFlagReadOnly
+)
+
+func (f FieldFlag) IsPrimaryKey() bool { return f&FieldFlagPrimaryKey != 0 }
+func (f FieldFlag) IsReadOnly() bool   { return f&FieldFlagReadOnly != 0 }
+
 // StructFieldNamer is used to map struct type fields to column names
-// and indicate if the column is a primary key.
+// and indicate special column properies via flags.
 type StructFieldNamer interface {
 	// StructFieldName returns the column name for reflected struct field
-	// and if the column is a primary key (pk).
-	// A name is returned for every ok field, non ok fields will be ignored.
-	StructFieldName(field reflect.StructField) (name string, pk, ok bool)
+	// and flags for special column properies.
+	// If the struct field can't be mapped, false is returned for ok.
+	StructFieldName(field reflect.StructField) (name string, flags FieldFlag, ok bool)
 }
 
 // DefaultStructFieldTagNaming provides the default StructFieldTagNaming
@@ -41,39 +53,49 @@ type StructFieldTagNaming struct {
 	UntaggedNameFunc func(fieldName string) string
 }
 
-func (n StructFieldTagNaming) StructFieldName(field reflect.StructField) (name string, pk, ok bool) {
+func (n StructFieldTagNaming) StructFieldName(field reflect.StructField) (name string, flags FieldFlag, ok bool) {
 	if field.Anonymous {
 		name, hasTag := field.Tag.Lookup(n.NameTag)
 		if !hasTag {
 			// Embedded struct fields are ok if not tagged with IgnoreName
-			return "", false, true
+			return "", 0, true
 		}
 		if i := strings.IndexByte(name, ','); i != -1 {
 			name = name[:i]
 		}
 		// Embedded struct fields are ok if not tagged with IgnoreName
-		return "", false, name != n.IgnoreName
+		return "", 0, name != n.IgnoreName
 	}
 	if field.PkgPath != "" {
 		// Not exported struct fields that are not
 		// anonymously embedded structs are not ok
-		return "", false, false
+		return "", 0, false
 	}
 
-	name, hasTag := field.Tag.Lookup(n.NameTag)
+	tag, hasTag := field.Tag.Lookup(n.NameTag)
 	if hasTag {
-		if i := strings.IndexByte(name, ','); i != -1 {
-			pk = name[i+1:] == "pk"
-			name = name[:i]
+		for i, part := range strings.Split(tag, ",") {
+			// First part is the name
+			if i == 0 {
+				name = part
+				continue
+			}
+			// Follow on parts are flags
+			switch part {
+			case "pk":
+				flags |= FieldFlagPrimaryKey
+			case "readonly":
+				flags |= FieldFlagReadOnly
+			}
 		}
 	} else {
 		name = n.UntaggedNameFunc(field.Name)
 	}
 
 	if name == "" || name == n.IgnoreName {
-		return "", false, false
+		return "", 0, false
 	}
-	return name, pk, true
+	return name, flags, true
 }
 
 func (n StructFieldTagNaming) String() string {
diff --git a/structfieldnamer_test.go b/structfieldnamer_test.go

Original file line number	Diff line number	Diff line change
`@@ -76,7 +76,7 @@ func UpdateStruct(conn sqldb.Connection, table string, rowStruct interface{}, na`
`76`	`76`	`return fmt.Errorf("UpdateStruct of table %s: expected struct but got %T", table, rowStruct)`
`77`	`77`	`}`
`78`	`78`
`79`		`- columns, pkCol, vals := structFields(v, namer, ignoreColumns, restrictToColumns, true)`
	`79`	`+ columns, flags, vals := structFields(v, namer, ignoreColumns, restrictToColumns, true)`
`80`	`80`	`if len(columns) == 0 {`
`81`	`81`	return fmt.Errorf("UpdateStruct of table %s: %T has no exported struct fields with `db` tag", table, rowStruct)
`82`	`82`	`}`
`@@ -85,7 +85,7 @@ func UpdateStruct(conn sqldb.Connection, table string, rowStruct interface{}, na`
`85`	`85`	fmt.Fprintf(&b, `UPDATE %s SET `, table)
`86`	`86`	`first := true`
`87`	`87`	`for i := range columns {`
`88`		`- if pkCol[i] {`
	`88`	`+ if f := flags[i]; f.IsPrimaryKey() \|\| f.IsReadOnly() {`
`89`	`89`	`continue`
`90`	`90`	`}`
`91`	`91`	`if first {`
`@@ -97,19 +97,19 @@ func UpdateStruct(conn sqldb.Connection, table string, rowStruct interface{}, na`
`97`	`97`	`}`
`98`	`98`
`99`	`99`	b.WriteString(` WHERE `)
`100`		`- first = true`
	`100`	`+ hasPK := false`
`101`	`101`	`for i := range columns {`
`102`		`- if !pkCol[i] {`
	`102`	`+ if !flags[i].IsPrimaryKey() {`
`103`	`103`	`continue`
`104`	`104`	`}`
`105`		`- if first {`
`106`		`- first = false`
	`105`	`+ if !hasPK {`
	`106`	`+ hasPK = true`
`107`	`107`	`} else {`
`108`	`108`	b.WriteString(` AND `)
`109`	`109`	`}`
`110`	`110`	fmt.Fprintf(&b, `"%s"=$%d`, columns[i], i+1)
`111`	`111`	`}`
`112`		`- if first {`
	`112`	`+ if !hasPK {`
`113`	`113`	`return fmt.Errorf("UpdateStruct of table %s: %T has no exported struct fields with ,pk tag value suffix to mark primary key column(s)", table, rowStruct)`
`114`	`114`	`}`
`115`	`115`	`query := b.String()`