plugin: pass the placeholder's name on Parameter rather than a flag

The name a placeholder carries, @name or {name:Type}, is what the
driver binds by, so the plugin Parameter carries it as name, collected
from the query's ParamRef nodes by the compiler rather than taken from
the analyzer, which also names a parameter after the function it is
compared with. The Go codegen passes it to sql.Named instead of the
column's name.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015rfiHyC4iRLyRWc3UmYEtT

Author: claude

internal/cmd/shim.go

@@ -258,7 +258,7 @@ func pluginQueryParam(p compiler.Parameter) *plugin.Parameter {
 	return &plugin.Parameter{
 		Number: int32(p.Number),
 		Column: pluginQueryColumn(p.Column),
-		Named:  p.Named,
+		Name:   p.Name,
 	}
 }
 

internal/codegen/golang/field.go

@@ -11,12 +11,15 @@ import (
 )
 
 type Field struct {
-	Name    string // CamelCased name for Go
-	DBName  string // Name as used in the DB
-	Type    string
-	Tags    map[string]string
-	Comment string
-	Column  *plugin.Column
+	Name   string // CamelCased name for Go
+	DBName string // Name as used in the DB
+	// ParamName is the name of the placeholder a parameter is bound by,
+	// when the query names it; empty otherwise and for row fields.
+	ParamName string
+	Type      string
+	Tags      map[string]string
+	Comment   string
+	Column    *plugin.Column
 	// EmbedFields contains the embedded fields that require scanning.
 	EmbedFields []Field
 }

internal/codegen/golang/query.go

@@ -15,6 +15,7 @@ type QueryValue struct {
 	EmitPointer bool
 	Name        string
 	DBName      string // The name of the field in the database. Only set if Struct==nil.
+	ParamName   string // The name of the placeholder a parameter is bound by, when the query names it. Only set if Struct==nil.
 	Struct      *Struct
 	Typ         string
 	SQLDriver   opts.SQLDriver
@@ -165,14 +166,14 @@ func (v QueryValue) Params() string {
 		if !v.Column.IsSqlcSlice && strings.HasPrefix(v.Typ, "[]") && v.Typ != "[]byte" && v.pqArrays() {
 			out = append(out, "pq.Array("+escape(v.Name)+")")
 		} else {
-			out = append(out, v.namedArg(v.DBName, escape(v.Name)))
+			out = append(out, v.namedArg(v.ParamName, escape(v.Name)))
 		}
 	} else {
 		for _, f := range v.Struct.Fields {
 			if !f.HasSqlcSlice() && strings.HasPrefix(f.Type, "[]") && f.Type != "[]byte" && v.pqArrays() {
 				out = append(out, "pq.Array("+escape(v.VariableForField(f))+")")
 			} else {
-				out = append(out, v.namedArg(f.DBName, escape(v.VariableForField(f))))
+				out = append(out, v.namedArg(f.ParamName, escape(v.VariableForField(f))))
 			}
 		}
 	}

internal/codegen/golang/result.go

@@ -115,6 +115,9 @@ type goColumn struct {
 	id int
 	*plugin.Column
 	embed *goEmbed
+	// paramName is the name of the placeholder a parameter is bound by,
+	// when the query names it.
+	paramName string
 }
 
 type goEmbed struct {
@@ -238,6 +241,7 @@ func buildQueries(req *plugin.GenerateRequest, options *opts.Options, enums []En
 			gq.Arg = QueryValue{
 				Name:           escape(paramName(p)),
 				DBName:         p.Column.GetName(),
+				ParamName:      p.Name,
 				Typ:            qualifyType(goParamType(req, options, p.Column), models, qualifier),
 				SQLDriver:      sqlpkg,
 				Engine:         req.Settings.Engine,
@@ -249,8 +253,9 @@ func buildQueries(req *plugin.GenerateRequest, options *opts.Options, enums []En
 			var cols []goColumn
 			for _, p := range query.Params {
 				cols = append(cols, goColumn{
-					id:     int(p.Number),
-					Column: p.Column,
+					id:        int(p.Number),
+					Column:    p.Column,
+					paramName: p.Name,
 				})
 			}
 			s, err := columnsToStruct(req, options, gq.MethodName+"Params", cols, false, models, qualifier)
@@ -422,10 +427,11 @@ func columnsToStruct(req *plugin.GenerateRequest, options *opts.Options, name st
 		}
 		addExtraGoStructTags(tags, req, options, c.Column)
 		f := Field{
-			Name:   fieldName,
-			DBName: colName,
-			Tags:   tags,
-			Column: c.Column,
+			Name:      fieldName,
+			DBName:    colName,
+			ParamName: c.paramName,
+			Tags:      tags,
+			Column:    c.Column,
 		}
 		if c.embed == nil {
 			// A row struct is scanned into, a params struct is passed as
@@ -487,16 +493,16 @@ func checkIncompatibleFieldTypes(fields []Field) error {
 }
 
 // placeholdersAreNamed reports whether every parameter of a query is bound
-// by name, which the compiler marks on a parameter whose placeholder names
-// it: SQL Server's and Spanner's @name and ClickHouse's {name:Type}, which
-// their drivers take as sql.Named. A query written with ? is bound by
-// position, so nothing is named unless every parameter is.
+// by name: the compiler passes the name a placeholder carries, SQL
+// Server's and Spanner's @name and ClickHouse's {name:Type}, which their
+// drivers take as sql.Named. A query written with ? is bound by position,
+// so nothing is named unless every parameter is.
 func placeholdersAreNamed(params []*plugin.Parameter) bool {
 	if len(params) == 0 {
 		return false
 	}
 	for _, p := range params {
-		if !p.Named || p.Column.GetName() == "" {
+		if p.Name == "" {
 			return false
 		}
 	}

internal/compiler/parse_core.go

@@ -10,6 +10,7 @@ import (
 	"github.com/sqlc-dev/sqlc/internal/metadata"
 	"github.com/sqlc-dev/sqlc/internal/source"
 	"github.com/sqlc-dev/sqlc/internal/sql/ast"
+	"github.com/sqlc-dev/sqlc/internal/sql/astutils"
 	"github.com/sqlc-dev/sqlc/internal/sql/named"
 	"github.com/sqlc-dev/sqlc/internal/sql/preprocess"
 	"github.com/sqlc-dev/sqlc/internal/sql/validate"
@@ -62,8 +63,9 @@ func (c *Compiler) parseQueryCore(raw *ast.RawStmt, src string, pre *preprocess.
 		for _, col := range res.Columns {
 			cols = append(cols, coreColumn(col))
 		}
+		placeholders := placeholderNames(raw)
 		for _, p := range res.Parameters {
-			params = append(params, Parameter{Number: p.Number, Column: coreParamColumn(p, namedParams), Named: p.Name != ""})
+			params = append(params, Parameter{Number: p.Number, Column: coreParamColumn(p, namedParams), Name: placeholders[p.Number]})
 		}
 		expanded, err = source.Mutate(rawSQL, c.expandCore(raw, res.Stars))
 		if err != nil {
@@ -136,6 +138,19 @@ func describeType(col *Column, t *core.TypeExpr) {
 	col.Unsigned = strings.HasSuffix(inner.Name, " unsigned")
 }
 
+// placeholderNames maps each parameter number to the name its placeholder
+// carries, for the placeholders that have one: @name and {name:Type}.
+func placeholderNames(root ast.Node) map[int]string {
+	names := map[int]string{}
+	astutils.Apply(root, func(c *astutils.Cursor) bool {
+		if pr, ok := c.Node().(*ast.ParamRef); ok && pr.Name != "" {
+			names[pr.Number] = pr.Name
+		}
+		return true
+	}, nil)
+	return names
+}
+
 func coreParamColumn(p core.Parameter, params *named.ParamSet) *Column {
 	col := &Column{
 		Name:     p.Name,

internal/compiler/query.go

@@ -64,7 +64,8 @@ type Query struct {
 type Parameter struct {
 	Number int
 	Column *Column
-	// Named is set when the query binds the parameter by name rather than
-	// by position: its placeholder is @name or {name:Type}.
-	Named bool
+	// Name is the name the placeholder itself carries, @name or
+	// {name:Type}, by which the query binds the parameter. It is empty for
+	// a positional placeholder.
+	Name string
 }

internal/endtoend/testdata/codegen_json/gen/codegen.json

@@ -68855,7 +68855,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         }
       ],
       "comments": [],
@@ -69071,7 +69071,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         },
         {
           "number": 2,
@@ -69102,7 +69102,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         }
       ],
       "comments": [],
@@ -69148,7 +69148,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         }
       ],
       "comments": [],

internal/endtoend/testdata/codegen_json_type_expr/gen/codegen.json

@@ -752,7 +752,7 @@
               "args": []
             }
           },
-          "named": false
+          "name": ""
         },
         {
           "number": 2,
@@ -796,7 +796,7 @@
               ]
             }
           },
-          "named": false
+          "name": ""
         }
       ],
       "comments": [],

internal/endtoend/testdata/process_plugin_sqlc_gen_json/gen/codegen.json

@@ -68857,7 +68857,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         }
       ],
       "comments": [],
@@ -69073,7 +69073,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         },
         {
           "number": 2,
@@ -69104,7 +69104,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         }
       ],
       "comments": [],
@@ -69150,7 +69150,7 @@
             "array_dims": 0,
             "type_expr": null
           },
-          "named": false
+          "name": ""
         }
       ],
       "comments": [],