feat(mysql): Add database analyzer for MySQL

Adds a MySQL database analyzer that validates queries against a real MySQL
database during code generation. This is similar to the existing PostgreSQL
and SQLite analyzers.

Key features:
- Creates managed databases (sqlc_managed_{hash}) based on migration content
- Validates query syntax using PrepareContext against real MySQL
- Detects parameter count from ? placeholders
- Gracefully handles missing database connections

Also fixes several MySQL test cases to use correct MySQL syntax:
- Changed $1/$2 placeholders to ? (MySQL syntax)
- Added AS aliases to count(*) expressions in CTEs
- Fixed column references and table aliases
- Removed PostgreSQL-specific public. schema prefix

Tests requiring MySQL-specific features (HeatWave VECTOR functions, SHOW
WARNINGS in prepared statements, etc.) are restricted to base context.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: kyleconroy

examples/authors/sqlc.yaml

@@ -24,6 +24,8 @@ sql:
   engine: mysql
   database:
     uri: "${VET_TEST_EXAMPLES_MYSQL_AUTHORS}"
+  analyzer:
+    database: false
   rules:
   - sqlc/db-prepare
   # - mysql-query-too-costly

examples/booktest/sqlc.json

@@ -30,6 +30,9 @@
       "database": {
         "uri": "${VET_TEST_EXAMPLES_MYSQL_BOOKTEST}"
       },
+      "analyzer": {
+        "database": false
+      },
       "rules": [
         "sqlc/db-prepare"
       ]

examples/ondeck/sqlc.json

@@ -33,6 +33,9 @@
       "database": {
         "uri": "${VET_TEST_EXAMPLES_MYSQL_ONDECK}"
       },
+      "analyzer": {
+        "database": false
+      },
       "rules": [
         "sqlc/db-prepare"
       ],

internal/compiler/analyze.go

@@ -77,25 +77,30 @@ func combineAnalysis(prev *analysis, a *analyzer.Analysis) *analysis {
 			Column: convertColumn(p.Column),
 		})
 	}
-	if len(prev.Columns) == len(cols) {
-		for i := range prev.Columns {
-			// Only override column types if the analyzer provides a specific type
-			// (not "any"), since the catalog-based inference may have better info
-			if cols[i].DataType != "any" {
-				prev.Columns[i].DataType = cols[i].DataType
-				prev.Columns[i].IsArray = cols[i].IsArray
-				prev.Columns[i].ArrayDims = cols[i].ArrayDims
+	// Only update columns if the analyzer returned column info
+	// An empty slice from the analyzer means it couldn't determine columns,
+	// so we should keep the catalog-inferred columns
+	if len(cols) > 0 {
+		if len(prev.Columns) == len(cols) {
+			for i := range prev.Columns {
+				// Only override column types if the analyzer provides a specific type
+				// (not "any"), since the catalog-based inference may have better info
+				if cols[i].DataType != "any" {
+					prev.Columns[i].DataType = cols[i].DataType
+					prev.Columns[i].IsArray = cols[i].IsArray
+					prev.Columns[i].ArrayDims = cols[i].ArrayDims
+				}
 			}
-		}
-	} else {
-		embedding := false
-		for i := range prev.Columns {
-			if prev.Columns[i].EmbedTable != nil {
-				embedding = true
+		} else {
+			embedding := false
+			for i := range prev.Columns {
+				if prev.Columns[i].EmbedTable != nil {
+					embedding = true
+				}
+			}
+			if !embedding {
+				prev.Columns = cols
 			}
-		}
-		if !embedding {
-			prev.Columns = cols
 		}
 	}
 	if len(prev.Parameters) == len(params) {

internal/compiler/engine.go

@@ -8,6 +8,7 @@ import (
 	"github.com/sqlc-dev/sqlc/internal/config"
 	"github.com/sqlc-dev/sqlc/internal/dbmanager"
 	"github.com/sqlc-dev/sqlc/internal/engine/dolphin"
+	mysqlanalyze "github.com/sqlc-dev/sqlc/internal/engine/dolphin/analyzer"
 	"github.com/sqlc-dev/sqlc/internal/engine/postgresql"
 	pganalyze "github.com/sqlc-dev/sqlc/internal/engine/postgresql/analyzer"
 	"github.com/sqlc-dev/sqlc/internal/engine/sqlite"
@@ -55,6 +56,15 @@ func NewCompiler(conf config.SQL, combo config.CombinedSettings) (*Compiler, err
 		c.parser = dolphin.NewParser()
 		c.catalog = dolphin.NewCatalog()
 		c.selector = newDefaultSelector()
+		if conf.Database != nil {
+			if conf.Analyzer.Database == nil || *conf.Analyzer.Database {
+				c.analyzer = analyzer.Cached(
+					mysqlanalyze.New(combo.Global.Servers, *conf.Database),
+					combo.Global,
+					*conf.Database,
+				)
+			}
+		}
 	case config.EnginePostgreSQL:
 		c.parser = postgresql.NewParser()
 		c.catalog = postgresql.NewCatalog()

internal/endtoend/testdata/create_view/mysql/go/query.sql.go

@@ -2,4 +2,4 @@
 SELECT * FROM first_view;
 
 -- name: GetSecond :many
-SELECT * FROM second_view WHERE val2 = $1;
+SELECT * FROM second_view WHERE val2 = ?;

internal/endtoend/testdata/create_view/mysql/query.sql

@@ -1,8 +1,8 @@
 -- name: CTECount :many
 WITH all_count AS (
-	SELECT count(*) FROM bar
+	SELECT count(*) AS count FROM bar
 ), ready_count AS (
-	SELECT count(*) FROM bar WHERE ready = true
+	SELECT count(*) AS count FROM bar WHERE ready = true
 )
 SELECT all_count.count, ready_count.count
 FROM all_count, ready_count;