{"record":{"id":"abf1580cd513d2e1","repo":"bytebase/bytebase","slug":"failed-to-parse-target-schema","errorCode":null,"errorMessage":"failed to parse target schema","messagePattern":"failed to parse target schema","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"backend/api/v1/database_service.go","lineNumber":1174,"sourceCode":"\t\tif dbMetadata == nil {\n\t\t\treturn nil, errors.Errorf(\"database schema not found for %s/%s\", instanceID, databaseID)\n\t\t}\n\t\treturn dbMetadata, nil\n\t}\n\n\t// If schema is provided, we need to parse it using GetDatabaseMetadata\n\tschemaStr := request.GetSchema()\n\tif schemaStr != \"\" {\n\t\t// Get the engine from the source database\n\t\tengine, err := s.getParserEngine(ctx, request)\n\t\tif err != nil {\n\t\t\treturn nil, errors.Wrapf(err, \"failed to get parser engine\")\n\t\t}\n\n\t\t// Parse the schema string into metadata\n\t\tmetadata, err := schema.GetDatabaseMetadata(engine, schemaStr)\n\t\tif err != nil {\n\t\t\treturn nil, errors.Wrapf(err, \"failed to parse target schema\")\n\t\t}\n\n\t\t// Get instance to determine case sensitivity\n\t\tprojectID, instanceID, _, err := common.GetDatabaseResourceName(request.Name)\n\t\tif err != nil {\n\t\t\treturn nil, err\n\t\t}\n\t\tinstance, err := s.getInstanceForDatabaseResource(ctx, projectID, instanceID)\n\t\tif err != nil {\n\t\t\treturn nil, err\n\t\t}\n\t\tif instance == nil {\n\t\t\treturn nil, errors.Errorf(\"instance %s not found\", instanceID)\n\t\t}\n\n\t\t// Create DatabaseSchema from the parsed metadata\n\t\treturn model.NewDatabaseMetadata(\n\t\t\tmetadata,","sourceCodeStart":1156,"sourceCodeEnd":1192,"githubUrl":"https://github.com/bytebase/bytebase/blob/1870550677fe08f0d2a78c07acd27541464eb945/backend/api/v1/database_service.go#L1156-L1192","documentation":"After resolving the parser engine, DiffSchema parses the user-supplied target DDL with schema.GetDatabaseMetadata. This wrap means the schema text failed to parse for the detected engine dialect, so no target metadata could be built.","triggerScenarios":"DiffSchema with request.schema set; schema.GetDatabaseMetadata(engine, schemaStr) returns a parse error, wrapped at backend/api/v1/database_service.go:1174.","commonSituations":"DDL written for a different dialect than the source database's engine (e.g. Postgres DDL against a MySQL instance), syntax errors or unsupported statements in the pasted schema, engine aliasing surprises (MariaDB/OceanBase parsed as MySQL), or an empty/truncated schema string.","solutions":["Read the wrapped cause to find the exact parse error line and fix the DDL syntax.","Ensure the schema dialect matches the source instance's engine (convert DDL if you diffed across engines).","Validate the DDL by applying it to a scratch database or a parser before calling DiffSchema.","Check the schema string is complete and non-empty (no truncation from the client)."],"exampleFix":"// before (Postgres DDL on a MySQL instance)\nrequest.Schema = \"CREATE TABLE t (id SERIAL PRIMARY KEY);\"\n// after (dialect-correct)\nrequest.Schema = \"CREATE TABLE t (id INT AUTO_INCREMENT PRIMARY KEY);\"","handlingStrategy":"validation","validationCode":"// lint the DDL against the right dialect before sending it\nimport { Parser } from 'sql-parser';\ntry {\n  Parser.parse(mysqlDialect, request.schema); // use the dialect matching the instance engine\n} catch (e) {\n  throw new Error(`target schema DDL invalid: ${e.message}`);\n}","typeGuard":"function isNonEmptySchema(s) { return typeof s === 'string' && s.trim().length > 0; }","tryCatchPattern":"try {\n  const diff = await api.DiffSchema(req);\n} catch (e) {\n  if (String(e.message).includes('failed to parse target schema')) {\n    // inspect e.cause for the exact line/column of the DDL parse failure\n  }\n  throw e;\n}","preventionTips":["Match the DDL dialect to the source instance engine before diffing","Validate DDL in a scratch database or linter first","Avoid dialect-specific syntax the engine's parser doesn't support","Ensure the schema string is not truncated or empty in transit"],"tags":["schema-diff","sql-parse","ddl"],"backgroundTag":"schema-validation-failed","analyzedSha":"1870550677fe08f0d2a78c07acd27541464eb945","analyzedAt":"2026-09-06T21:16:13.665Z","contentChangedAt":"2026-09-06T21:16:13.665Z","schemaVersion":2},"datasetVersion":"2026-09-14T05:17:10.506Z"}