fix(ddl): resolve DDL view formatting dialect by database type

apps/desktop/src/lib/sql/__tests__/ddlDisplay.spec.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { formatGeneratedDdlIdentifierQuotes, omitDdlDatabaseQualifier, omitDdlIdentifierQuotes } from "@/lib/sql/ddlDisplay";
+import { ddlFormatDialectFor, formatGeneratedDdlIdentifierQuotes, omitDdlDatabaseQualifier, omitDdlIdentifierQuotes } from "@/lib/sql/ddlDisplay";
 
 describe("omitDdlDatabaseQualifier", () => {
   it("drops the schema qualifier from Oracle table DDL without touching tablespace references", () => {
@@ -109,3 +109,29 @@ describe("omitDdlIdentifierQuotes", () => {
     expect(formatGeneratedDdlIdentifierQuotes(ddl, "oracle", true)).toBe(ddl);
   });
 });
+
+describe("ddlFormatDialectFor", () => {
+  it("prefers the effective database type over an Oracle-like connection's MySQL highlighting dialect", () => {
+    expect(ddlFormatDialectFor({ databaseType: "oracle", highlightDialect: "mysql" })).toBe("oracle");
+    expect(ddlFormatDialectFor({ databaseType: "dameng", highlightDialect: "mysql" })).toBe("dameng");
+    expect(ddlFormatDialectFor({ databaseType: "kingbase", highlightDialect: "mysql" })).toBe("postgres");
+  });
+
+  it("honors an explicit formatter dialect first", () => {
+    expect(ddlFormatDialectFor({ formatDialect: "sqlserver", databaseType: "oracle", highlightDialect: "mysql" })).toBe("sqlserver");
+  });
+
+  it("keeps the highlighting dialect when the database type has no dedicated formatter dialect", () => {
+    expect(ddlFormatDialectFor({ databaseType: "db2", highlightDialect: "mysql" })).toBe("mysql");
+    expect(ddlFormatDialectFor({ highlightDialect: "postgres" })).toBe("postgres");
+    expect(ddlFormatDialectFor({})).toBe("generic");
+  });
+
+  it("keeps case-sensitive quoted Oracle names quoted in the DDL view", () => {
+    const ddl = 'CREATE TABLE "SYSTEM"."TEST" ("id" VARCHAR2(32), "cName" VARCHAR2(100))';
+    const highlightDialect = "mysql";
+    const resolved = ddlFormatDialectFor({ databaseType: "oracle", highlightDialect });
+    expect(omitDdlIdentifierQuotes(ddl, highlightDialect)).toBe("CREATE TABLE SYSTEM.TEST (id VARCHAR2(32), cName VARCHAR2(100))");
+    expect(omitDdlIdentifierQuotes(ddl, resolved)).toBe('CREATE TABLE SYSTEM.TEST ("id" VARCHAR2(32), "cName" VARCHAR2(100))');
+  });
+});

apps/desktop/src/lib/sql/ddlDisplay.ts

@@ -1,7 +1,7 @@
 import { requiresDamengIdentifierQuote, requiresMysqlIdentifierQuote, requiresOracleIdentifierQuote, requiresPostgresIdentifierQuote } from "@/lib/sql/sqlIdentifier";
 import { tokenIsIdentifier, tokenizeSqlSemantic, unquoteSqlSemanticIdentifier } from "@/lib/sql/semantic/tokens";
 import type { SqlSemanticToken } from "@/lib/sql/semantic/types";
-import type { SqlFormatDialect } from "@/lib/sql/sqlFormatter";
+import { sqlFormatDialectForDbType, type SqlFormatDialect } from "@/lib/sql/sqlFormatter";
 import { dropsSchemaQualifier } from "@/lib/table/tableSelectSql";
 import type { DatabaseType } from "@/types/database";
 
@@ -28,6 +28,21 @@ function canRenderUnquoted(identifier: string, dialect: SqlFormatDialect): boole
   }
 }
 
+/**
+ * Resolve the dialect used to read and rewrite DDL text. Callers that only
+ * know the connection's syntax-highlighting dialect (which collapses every
+ * Oracle-like database onto MySQL) must not have that value decide identifier
+ * quoting rules: a case-sensitive Oracle/Dameng name such as `"cName"` would
+ * lose its quotes. The effective database type wins, the highlighting dialect
+ * stays as the fallback for unmapped types.
+ */
+export function ddlFormatDialectFor(options: { formatDialect?: SqlFormatDialect; databaseType?: DatabaseType; highlightDialect?: SqlFormatDialect }): SqlFormatDialect {
+  if (options.formatDialect) return options.formatDialect;
+  const fromDatabaseType = options.databaseType ? sqlFormatDialectForDbType(options.databaseType) : undefined;
+  if (fromDatabaseType && fromDatabaseType !== "generic") return fromDatabaseType;
+  return options.highlightDialect ?? fromDatabaseType ?? "generic";
+}
+
 /** Removes dialect identifier quotes from safe names while preserving strings, comments, and unsafe names. */
 export function omitDdlIdentifierQuotes(sql: string, dialect: SqlFormatDialect): string {
   const tokens = tokenizeSqlSemantic(sql, dialect === "sqlserver" ? "sqlserver" : dialect);