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/$2 placeholders to ? (MySQL syntax) - Added AS aliases to count(*) expressions in CTEs - Fixed column references and table aliases - Removed PostgreSQL-specific public. schema prefix Tests requiring MySQL-specific features (HeatWave VECTOR functions, SHOW WARNINGS in prepared statements, etc.) are restricted to base context. 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude <[email protected]>
sqlc-dev · kyleconroy · Nov 29, 2025 · Nov 30, 2025 · Nov 29, 2025 · e52cd4e2e85822106193e0c82b469f7de1eadc55
commit e52cd4e2e85822106193e0c82b469f7de1eadc55
diff --git a/examples/authors/sqlc.yaml b/examples/authors/sqlc.yaml
@@ -24,6 +24,8 @@ sql:
   engine: mysql
   database:
     uri: "${VET_TEST_EXAMPLES_MYSQL_AUTHORS}"
+  analyzer:
+    database: false
   rules:
   - sqlc/db-prepare
   # - mysql-query-too-costly

diff --git a/examples/booktest/sqlc.json b/examples/booktest/sqlc.json
@@ -30,6 +30,9 @@
       "database": {
         "uri": "${VET_TEST_EXAMPLES_MYSQL_BOOKTEST}"
       },
+      "analyzer": {
+        "database": false
+      },
       "rules": [
         "sqlc/db-prepare"
       ]

diff --git a/examples/ondeck/sqlc.json b/examples/ondeck/sqlc.json
@@ -33,6 +33,9 @@
       "database": {
         "uri": "${VET_TEST_EXAMPLES_MYSQL_ONDECK}"
       },
+      "analyzer": {
+        "database": false
+      },
       "rules": [
         "sqlc/db-prepare"
       ],

diff --git a/internal/compiler/analyze.go b/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) {

diff --git a/internal/compiler/engine.go b/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()

diff --git a/internal/endtoend/testdata/create_view/mysql/go/query.sql.go b/internal/endtoend/testdata/create_view/mysql/go/query.sql.go
diff --git a/internal/endtoend/testdata/create_view/mysql/query.sql b/internal/endtoend/testdata/create_view/mysql/query.sql
@@ -2,4 +2,4 @@
 SELECT * FROM first_view;
 
 -- name: GetSecond :many
-SELECT * FROM second_view WHERE val2 = $1;
+SELECT * FROM second_view WHERE val2 = ?;
diff --git a/internal/endtoend/testdata/cte_count/mysql/go/query.sql.go b/internal/endtoend/testdata/cte_count/mysql/go/query.sql.go
diff --git a/internal/endtoend/testdata/cte_count/mysql/query.sql b/internal/endtoend/testdata/cte_count/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;
diff --git a/internal/endtoend/testdata/cte_filter/mysql/go/query.sql.go b/internal/endtoend/testdata/cte_filter/mysql/go/query.sql.go
diff --git a/internal/endtoend/testdata/cte_filter/mysql/query.sql b/internal/endtoend/testdata/cte_filter/mysql/query.sql
@@ -1,6 +1,6 @@
 -- name: CTEFilter :many
 WITH filter_count AS (
-	SELECT count(*) FROM bar WHERE ready = ?
+	SELECT count(*) AS count FROM bar WHERE ready = ?
 )
 SELECT filter_count.count
 FROM filter_count;
diff --git a/internal/endtoend/testdata/in_union/mysql/go/query.sql.go b/internal/endtoend/testdata/in_union/mysql/go/query.sql.go
diff --git a/internal/endtoend/testdata/in_union/mysql/query.sql b/internal/endtoend/testdata/in_union/mysql/query.sql
@@ -1,3 +1,3 @@
 -- name: GetAuthors :many
 SELECT * FROM authors
-WHERE author_id IN (SELECT author_id FROM book1 UNION SELECT author_id FROM book2);
+WHERE id IN (SELECT author_id FROM book1 UNION SELECT author_id FROM book2);
diff --git a/internal/endtoend/testdata/insert_select_invalid/mysql/exec.json b/internal/endtoend/testdata/insert_select_invalid/mysql/exec.json
@@ -0,0 +1,3 @@
+{
+    "contexts": ["base"]
+}
diff --git a/internal/endtoend/testdata/insert_values_public/mysql/go/query.sql.go b/internal/endtoend/testdata/insert_values_public/mysql/go/query.sql.go
diff --git a/internal/endtoend/testdata/insert_values_public/mysql/query.sql b/internal/endtoend/testdata/insert_values_public/mysql/query.sql
@@ -1,2 +1,2 @@
 /* name: InsertValues :exec */
-INSERT INTO public.foo (a, b) VALUES (?, ?);
+INSERT INTO foo (a, b) VALUES (?, ?);
diff --git a/internal/endtoend/testdata/invalid_group_by_reference/mysql/exec.json b/internal/endtoend/testdata/invalid_group_by_reference/mysql/exec.json
@@ -1,4 +1,5 @@
 {
+    "contexts": ["base"],
     "meta": {
         "invalid_schema": true
     }

diff --git a/internal/endtoend/testdata/invalid_table_alias/mysql/exec.json b/internal/endtoend/testdata/invalid_table_alias/mysql/exec.json
@@ -0,0 +1,3 @@
+{
+    "contexts": ["base"]
+}
diff --git a/internal/endtoend/testdata/join_left_same_table/mysql/go/query.sql.go b/internal/endtoend/testdata/join_left_same_table/mysql/go/query.sql.go
diff --git a/internal/endtoend/testdata/join_left_same_table/mysql/query.sql b/internal/endtoend/testdata/join_left_same_table/mysql/query.sql
@@ -5,4 +5,4 @@ SELECT  a.id,
         p.name as alias_name
 FROM    authors a
         LEFT JOIN authors p
-            ON (authors.parent_id = p.id);
+            ON (a.parent_id = p.id);
diff --git a/internal/endtoend/testdata/mysql_vector/mysql/exec.json b/internal/endtoend/testdata/mysql_vector/mysql/exec.json
@@ -0,0 +1,3 @@
+{
+    "contexts": ["base"]
+}
diff --git a/internal/endtoend/testdata/select_subquery_no_alias/mysql/exec.json b/internal/endtoend/testdata/select_subquery_no_alias/mysql/exec.json
@@ -0,0 +1,3 @@
+{
+    "contexts": ["base"]
+}
diff --git a/internal/endtoend/testdata/show_warnings/mysql/exec.json b/internal/endtoend/testdata/show_warnings/mysql/exec.json
@@ -0,0 +1,3 @@
+{
+    "contexts": ["base"]
+}
diff --git a/internal/endtoend/testdata/valid_group_by_reference/mysql/exec.json b/internal/endtoend/testdata/valid_group_by_reference/mysql/exec.json
@@ -0,0 +1,3 @@
+{
+    "contexts": ["base"]
+}
diff --git a/internal/endtoend/testdata/vet_explain/mysql/exec.json b/internal/endtoend/testdata/vet_explain/mysql/exec.json
@@ -0,0 +1,3 @@
+{
+    "contexts": ["managed-db"]
+}
diff --git a/internal/endtoend/testdata/wrap_errors/mysql/db/query.sql.go b/internal/endtoend/testdata/wrap_errors/mysql/db/query.sql.go
diff --git a/internal/endtoend/testdata/wrap_errors/mysql/query.sql b/internal/endtoend/testdata/wrap_errors/mysql/query.sql
@@ -1,6 +1,6 @@
 -- name: GetAuthor :one
 SELECT * FROM authors
-WHERE id = $1 LIMIT 1;
+WHERE id = ? LIMIT 1;
 
 -- name: ListAuthors :many
 SELECT * FROM authors
@@ -10,21 +10,21 @@ ORDER BY name;
 INSERT INTO authors (
           name, bio
 ) VALUES (
-  $1, $2
+  ?, ?
 );
 
 -- name: DeleteAuthorExec :exec
 DELETE FROM authors
-WHERE id = $1;
+WHERE id = ?;
 
 -- name: DeleteAuthorExecRows :execrows
 DELETE FROM authors
-WHERE id = $1;
+WHERE id = ?;
 
 -- name: DeleteAuthorExecLastID :execlastid
 DELETE FROM authors
-WHERE id = $1;
+WHERE id = ?;
 
 -- name: DeleteAuthorExecResult :execresult
 DELETE FROM authors
-WHERE id = $1;
+WHERE id = ?;