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writing-sql

Write SQL queries for Celigo RDBMS exports and imports -- SELECT, INSERT, UPDATE, UPSERT, MERGE, delta, once, and bulk operations across Snowflake, Postgres, MySQL, SQL Server, Oracle, BigQuery, and Redshift. Use when editing rdbms.query or troubleshooting SQL errors.

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Skill instructions

Rendered from the published SKILL.md, 555 lines.

Writing SQL for RDBMS Integrations

RDBMS exports and imports use SQL queries to read from and write to relational databases. Queries are Handlebars templates -- the platform evaluates expressions like {{{record.fieldName}}} at runtime, then executes the resulting SQL against the connected database.

This skill covers what SQL to write and how to write it. For which adaptor type to use, connection setup, and queryType selection, see the related skills below. When the task is to create an export or import, create it with the query in place rather than handing back the SQL -- Delta export shows a complete export.

Quick Reference

Context decision matrix

Where Field Handlebars prefix Braces Example
Export query rdbms.query record. (parameterized) or none (standalone) {{{ }}} SELECT * FROM orders WHERE id = {{{record.id}}}
Export delta query rdbms.query platform-injected tokens {{ }} (adds the quotes) WHERE updated_at > {{lastExportDateTime}}
Export once mark-as-processed rdbms.once.query record. {{{ }}} UPDATE orders SET exported = true WHERE id = {{{record.id}}}
Import per_record query rdbms.query[] record. {{ }} strings, {{{ }}} numbers INSERT INTO users (name, age) VALUES ({{record.name}}, {{{record.age}}})
Import per_page query rdbms.query[] batch_of_records + record. {{ }} strings, {{{ }}} numbers {{#each batch_of_records}}...{{record.field}}...{{/each}}
Import bulk_load override rdbms.bulkLoad.overrideMergeQuery staging table ref {{ }} MERGE INTO target USING {{import.rdbms.bulkLoad.preMergeTemporaryTable}}

Key syntax rules

  1. Always use record. prefix (AFE 2.0). Never bare fieldName or data.fieldName.
  2. Double braces quote strings for you. {{record.name}} renders a single-quoted SQL string literal with embedded quotes doubled (O'Neil Co renders 'O''Neil Co'), and so does every other string an expression produces: helper output such as {{dateFormat ...}} or {{jsonSerialize ...}}, and {{this}} inside {{#each}}. Use it for string and date values, including {{lastExportDateTime}}, and never add quotes around it -- '{{record.name}}' renders doubled quotes. On Snowflake, a value holding a backslash needs another form (gotcha 13).
  3. Triple braces are raw. Use {{{ }}} for numbers ({{{record.quantity}}} -- a number that arrives as a string, "5", renders '5' in double braces; JSON numbers and booleans render bare either way), identifiers such as table or column names, and SQL fragments you built yourself. Never wrap a triple-brace string in single quotes of your own ('{{{record.name}}}'): the first apostrophe in the data breaks the statement and leaves it open to SQL injection. (Snowflake's dollar-quoted constants are the one exception, in gotcha 13.)
  4. Import query is an array of strings, not a single string: ["INSERT INTO ..."].
  5. Nested fields use dot notation: {{record.address.city}}.

Related skills

Schema reference

How to Write a SQL Query

1. Discover the schema

Query the live database to find tables and columns before writing SQL:

celigo metadata types <connectionId>                    # List tables
celigo metadata fields <connectionId> <tableName>       # List columns and types

For Snowflake, use fully qualified names: database.schema.table.

2. Determine the query pattern

Exports -- what kind of data fetch?

Pattern Export type Query template
Full fetch type: null SELECT columns FROM table WHERE conditions
Delta/incremental type: "delta" SELECT ... WHERE updated_at > {{lastExportDateTime}}
Once (mark-as-processed) type: "once" rdbms.query = SELECT unprocessed; rdbms.once.query = UPDATE to mark processed

Imports -- what kind of write operation? (The bulk_load rows apply to Snowflake, Google BigQuery, Microsoft SQL Server on a cloud connection, Azure Synapse and Amazon Redshift, and to NSAW through the JDBC import.) Pick the fastest type the operation allows: bulk_load where the database has it, bulk_insert for pure inserts, then per_page -- one statement per page, rendered against batch_of_records, so it must cover the whole batch -- and per_record when the SQL can't be written for a page.

Pattern queryType What to configure
INSERT with duplicate check ["per_page"] or ["per_record"] rdbms.query with INSERT ... ON CONFLICT / ON DUPLICATE KEY -- per_page as one multi-row statement
UPDATE ["per_page"] or ["per_record"] rdbms.query with UPDATE ... WHERE, or one statement that updates the whole page
UPSERT / MERGE ["bulk_load"], else ["per_page"] or ["per_record"] bulk_load: bulkLoad.primaryKeys; otherwise rdbms.query with MERGE or ON CONFLICT
Pure INSERT (no checking) ["bulk_insert"] rdbms.bulkInsert.tableName and batchSize -- no SQL needed
Bulk load with upsert ["bulk_load"] rdbms.bulkLoad.tableName and primaryKeys -- auto-generates MERGE
Custom bulk merge ["bulk_load"] bulkLoad.overrideMergeQuery: true + custom SQL referencing staging table

3. Write the SQL

Follow the database-specific dialect patterns below. Inject runtime values with {{record.fieldName}} for strings and dates and {{{record.fieldName}}} for numbers and identifiers (see Key syntax rules).

4. Test the query

An export query can be tried before it's saved: a preview of an unsaved export document runs its query and saves nothing. For a delta query, give the document postData with both variables, or they render empty and the SQL doesn't compile (Delta export).

# Test an export query -- invoke returns real data
celigo exports invoke <exportId>
celigo exports invoke --file export.json    # an unsaved document; nothing is saved

# Test an import -- a real write: the records are written to the database
echo '[{"name":"test","email":"test@example.com"}]' | celigo imports invoke <importId>

Nothing shows an import's SQL without running it. A flow test run never executes imports, an import preview (celigo imports invoke with a document) answers 422 invalid_adaptor for an RDBMS import, and the Handlebars processor HTML-escapes values instead of quoting them (O'Neil & Co renders O&#x27;Neil &amp; Co), so its output isn't what the database receives. Check the statement in the import editor's SQL preview, then run one record against a test table.

Export Query Patterns

Standard SELECT

SELECT id, name, email, status
FROM customers
WHERE status = 'ACTIVE'
ORDER BY id

Delta export (incremental)

Use {{lastExportDateTime}} (platform-injected, not from a record). It is the start of the run's window: the end of the last run that exported records, or delta.startDate on a new export's first run. It renders as a quoted ISO 8601 UTC literal with milliseconds ('2026-01-15T00:00:00.000Z'), so don't add quotes of your own: '{{lastExportDateTime}}' doubles the quotes, and a bare {{{lastExportDateTime}}} is an unquoted timestamp -- both are SQL errors. {{currentExportDateTime}} is the window's end; never use it as the lower bound.

Set delta.startDate on the export. Without it, the first run's {{lastExportDateTime}} is the run's own time, and the first run exports nothing. A complete delta export:

{
  "name": "Changed customers",
  "adaptorType": "RDBMSExport",
  "_connectionId": "<rdbmsConnectionId>",
  "type": "delta",
  "delta": { "startDate": "2026-10-01T00:00:00.000Z" },
Show the whole skill (435 more lines)

"rdbms": { "query": "SELECT id, name, email, updated_at FROM customers WHERE updated_at > {{lastExportDateTime}} ORDER BY updated_at ASC" } }


Snowflake compares the literal with a timestamp column directly. Where the database needs a timestamp value or another format:

```sql
-- Snowflake: let TO_TIMESTAMP detect the ISO 8601 format (a 'YYYY-MM-DD HH24:MI:SS' mask returns null or fails)
WHERE updated_at > TO_TIMESTAMP({{lastExportDateTime}})

-- PostgreSQL: cast to timestamptz -- ::timestamp ignores the trailing Z
WHERE updated_at > {{lastExportDateTime}}::timestamptz

-- MySQL and others: set delta.dateFormat on the export (e.g. "YYYY-MM-DD HH:mm:ss"),
-- which formats both variables in the query, then compare directly
WHERE updated_at > {{lastExportDateTime}}

A preview of an unsaved export document renders both variables empty and unquoted, so the query fails there unless the document supplies both in postData (configuring-exports > Gotchas, 18). In a flow run, remember that a run given its own window (flows run --start-time/--end-time) leaves the checkpoint at its end time.

Once export (mark-as-processed)

Two queries work together. The export rdbms.query fetches unprocessed records; rdbms.once.query marks each one after successful export.

{
  "type": "once",
  "rdbms": {
    "query": "SELECT id, name, email FROM orders WHERE exported = false",
    "once": {
      "query": "UPDATE orders SET exported = true WHERE id = {{{record.id}}}"
    }
  }
}

JOINs

SELECT o.id, o.order_date, c.name AS customer_name, c.email,
       p.product_name, oi.quantity, oi.unit_price
FROM orders o
JOIN customers c ON o.customer_id = c.id
JOIN order_items oi ON o.id = oi.order_id
JOIN products p ON oi.product_id = p.id
WHERE o.status = 'SHIPPED'
  AND o.order_date > {{lastExportDateTime}}

Aggregations

SELECT customer_id, COUNT(*) AS order_count, SUM(total) AS lifetime_value
FROM orders
WHERE status IN ('COMPLETED', 'SHIPPED')
GROUP BY customer_id
HAVING SUM(total) > 1000

Import Query Patterns

All import queries inject values from incoming records with record. paths -- {{ }} for strings and dates (quoted and escaped for you), {{{ }}} for numbers. The query field is an array of strings.

INSERT (per_record)

{
  "rdbms": {
    "queryType": ["per_record"],
    "query": ["INSERT INTO customers (name, email, phone) VALUES ({{record.name}}, {{record.email}}, {{record.phone}})"]
  }
}

UPDATE (per_record)

{
  "rdbms": {
    "queryType": ["per_record"],
    "query": ["UPDATE customers SET name = {{record.name}}, email = {{record.email}} WHERE id = {{{record.id}}}"]
  }
}

UPSERT -- database-specific

MySQL (ON DUPLICATE KEY UPDATE):

{
  "rdbms": {
    "queryType": ["per_record"],
    "query": ["INSERT INTO customers (id, name, email) VALUES ({{{record.id}}}, {{record.name}}, {{record.email}}) ON DUPLICATE KEY UPDATE name = {{record.name}}, email = {{record.email}}"]
  }
}

PostgreSQL (ON CONFLICT):

{
  "rdbms": {
    "queryType": ["per_record"],
    "query": ["INSERT INTO customers (id, name, email) VALUES ({{{record.id}}}, {{record.name}}, {{record.email}}) ON CONFLICT (id) DO UPDATE SET name = EXCLUDED.name, email = EXCLUDED.email"]
  }
}

Snowflake (MERGE):

{
  "rdbms": {
    "queryType": ["per_record"],
    "query": ["MERGE INTO customers AS t USING (SELECT {{{record.id}}} AS id, {{record.name}} AS name, {{record.email}} AS email) AS s ON t.id = s.id WHEN MATCHED THEN UPDATE SET t.name = s.name, t.email = s.email WHEN NOT MATCHED THEN INSERT (id, name, email) VALUES (s.id, s.name, s.email)"]
  }
}

SQL Server (MERGE):

{
  "rdbms": {
    "queryType": ["per_record"],
    "query": ["MERGE INTO customers AS t USING (SELECT {{{record.id}}} AS id, {{record.name}} AS name, {{record.email}} AS email) AS s ON t.id = s.id WHEN MATCHED THEN UPDATE SET t.name = s.name, t.email = s.email WHEN NOT MATCHED THEN INSERT (id, name, email) VALUES (s.id, s.name, s.email);"]
  }
}

Multiple statements (per_record)

When you need to run multiple SQL statements per record, add them as separate array elements:

{
  "rdbms": {
    "queryType": ["per_record"],
    "query": [
      "INSERT INTO orders (id, customer_id, total) VALUES ({{{record.orderId}}}, {{{record.customerId}}}, {{{record.total}}})",
      "UPDATE customers SET last_order_date = CURRENT_TIMESTAMP WHERE id = {{{record.customerId}}}"
    ]
  }
}

Bulk insert (no SQL needed)

For pure INSERTs with no duplicate checking, use bulkInsert -- the platform generates the SQL:

{
  "rdbms": {
    "queryType": ["bulk_insert"],
    "bulkInsert": {
      "tableName": "customers",
      "batchSize": "1000"
    }
  }
}

Column mapping comes from mappings[] on the import (Mapper 2.0). Each mapping's generate value must match a column name in the target table, and each needs a dataType -- string, number or boolean for a column value; a timestamp is a string, since there is no date type (see writing-mappings).

Bulk load with auto-generated MERGE

bulk_load is available on Snowflake, Google BigQuery, Microsoft SQL Server (a cloud connection, not one through an on-premise agent), Azure Synapse and Amazon Redshift, and on NSAW through the JDBC import. Redshift needs no AWS setup for it: Celigo stages the files and Redshift loads them with COPY. The import form shows the option on BigQuery, SQL Server, Synapse and Redshift only when it's enabled for the account, but the API accepts the import either way. On other databases (MySQL, MariaDB, PostgreSQL, Oracle), use bulk_insert for pure inserts and per_page or per_record SQL for updates and upserts. On a supported database, a high-volume upsert uses bulkLoad with primaryKeys, an array of column names:

{
  "rdbms": {
    "queryType": ["bulk_load"],
    "bulkLoad": {
      "tableName": "WAREHOUSE.PUBLIC.CUSTOMERS",
      "primaryKeys": ["ID"]
    }
  }
}

The platform stages data into a temporary table, then auto-generates a MERGE using the primary keys. primaryKeys is an array even for one column, never a string; for composite keys, list each column: "primaryKeys": ["ORDER_ID", "PRODUCT_ID"]. Without primaryKeys the load is a plain insert, and without tableName the save is refused with 422 "rdbms imports require a tableName."

Bulk load with custom merge

When the auto-generated MERGE isn't sufficient (conditional updates, ignore-existing, multi-table ops), override it:

{
  "rdbms": {
    "queryType": ["bulk_load"],
    "bulkLoad": {
      "tableName": "WAREHOUSE.PUBLIC.CUSTOMERS",
      "primaryKeys": ["ID"],
      "overrideMergeQuery": true
    }
  }
}

The custom SQL goes in the rdbms.query field (yes, even with bulkLoad). Reference the staging table via {{import.rdbms.bulkLoad.preMergeTemporaryTable}}:

MERGE INTO WAREHOUSE.PUBLIC.CUSTOMERS AS t
USING {{import.rdbms.bulkLoad.preMergeTemporaryTable}} AS s
ON t.id = s.id
WHEN MATCHED AND s.updated_at > t.updated_at THEN
  UPDATE SET t.name = s.name, t.email = s.email, t.updated_at = s.updated_at
WHEN NOT MATCHED THEN
  INSERT (id, name, email, updated_at) VALUES (s.id, s.name, s.email, s.updated_at)

per_page batch operations

per_page gives you the entire page of records as batch_of_records. Use {{#each}} to iterate:

{
  "rdbms": {
    "queryType": ["per_page"],
    "query": ["INSERT INTO customers (name, email) VALUES {{#each batch_of_records}}({{record.name}}, {{record.email}}){{#unless @last}},{{/unless}}{{/each}}"]
  }
}

Dialect Patterns

Snowflake

-- Fully qualified table names (required unless connection sets default schema)
SELECT * FROM MY_DATABASE.MY_SCHEMA.MY_TABLE

-- FLATTEN for semi-structured data (VARIANT columns)
SELECT f.value:name::STRING AS name, f.value:email::STRING AS email
FROM MY_TABLE, LATERAL FLATTEN(input => MY_TABLE.json_column) f

-- JSON into a VARIANT column: a dollar-quoted constant keeps every character (data must not contain $$), while
-- PARSE_JSON({{jsonSerialize record.payload}}) fails on a double quote or line break in the data (gotcha 13)
INSERT INTO MY_DATABASE.MY_SCHEMA.EVENTS (PAYLOAD) SELECT PARSE_JSON($${{{jsonSerialize record.payload}}}$$)

-- QUALIFY for window function filtering
SELECT * FROM orders
QUALIFY ROW_NUMBER() OVER (PARTITION BY customer_id ORDER BY order_date DESC) = 1

-- Timestamp handling: the delta literal compares directly, or let TO_TIMESTAMP detect its format
WHERE updated_at > TO_TIMESTAMP({{lastExportDateTime}})

-- Case: Snowflake uppercases unquoted identifiers. Use double quotes to preserve case
SELECT "camelCaseColumn" FROM "MixedCaseTable"

PostgreSQL

-- JSONB operators
SELECT data->>'name' AS name, data->'address'->>'city' AS city
FROM customers WHERE data @> '{"active": true}'

-- ILIKE for case-insensitive matching
SELECT * FROM products WHERE name ILIKE '%widget%'

-- ON CONFLICT for upsert
INSERT INTO customers (id, name, email) VALUES ({{{record.id}}}, {{record.name}}, {{record.email}})
ON CONFLICT (id) DO UPDATE SET name = EXCLUDED.name, email = EXCLUDED.email

-- Array operations
SELECT * FROM users WHERE 'admin' = ANY(roles)

-- CTEs
WITH recent_orders AS (
  SELECT * FROM orders WHERE order_date > {{lastExportDateTime}}
)
SELECT c.name, r.total FROM customers c JOIN recent_orders r ON c.id = r.customer_id

MySQL / MariaDB

-- ON DUPLICATE KEY UPDATE for upsert
INSERT INTO customers (id, name, email)
VALUES ({{{record.id}}}, {{record.name}}, {{record.email}})
ON DUPLICATE KEY UPDATE name = VALUES(name), email = VALUES(email)

-- JSON_EXTRACT for JSON columns
SELECT JSON_EXTRACT(data, '$.name') AS name FROM customers

-- GROUP_CONCAT for string aggregation
SELECT customer_id, GROUP_CONCAT(product_name SEPARATOR ', ') AS products
FROM order_items GROUP BY customer_id

-- IFNULL for null handling
SELECT IFNULL(middle_name, '') AS middle_name FROM users

-- Delta timestamps: set delta.dateFormat "YYYY-MM-DD HH:mm:ss" on the export, then compare directly
WHERE updated_at > {{lastExportDateTime}}

SQL Server / Azure Synapse

-- MERGE with required semicolon terminator
MERGE INTO customers AS t
USING (SELECT {{{record.id}}} AS id, {{record.name}} AS name) AS s
ON t.id = s.id
WHEN MATCHED THEN UPDATE SET t.name = s.name
WHEN NOT MATCHED THEN INSERT (id, name) VALUES (s.id, s.name);

-- TOP instead of LIMIT
SELECT TOP 100 * FROM orders ORDER BY order_date DESC

-- STRING_AGG for string aggregation (SQL Server 2017+)
SELECT customer_id, STRING_AGG(product_name, ', ') AS products
FROM order_items GROUP BY customer_id

-- CROSS APPLY for row-valued functions
SELECT c.name, o.total FROM customers c
CROSS APPLY (SELECT TOP 1 * FROM orders WHERE customer_id = c.id ORDER BY order_date DESC) o

-- Bracket identifiers for reserved words or special characters
SELECT [order], [name] FROM [my-table]

Oracle

-- NVL for null handling
SELECT NVL(middle_name, '') AS middle_name FROM users

-- ROWNUM for limiting results (pre-12c)
SELECT * FROM (SELECT * FROM orders ORDER BY order_date DESC) WHERE ROWNUM <= 100

-- FETCH FIRST for limiting results (12c+)
SELECT * FROM orders ORDER BY order_date DESC FETCH FIRST 100 ROWS ONLY

-- LISTAGG for string aggregation
SELECT customer_id, LISTAGG(product_name, ', ') WITHIN GROUP (ORDER BY product_name)
FROM order_items GROUP BY customer_id

-- MERGE
MERGE INTO customers t USING (SELECT {{{record.id}}} AS id, {{record.name}} AS name FROM dual) s
ON (t.id = s.id)
WHEN MATCHED THEN UPDATE SET t.name = s.name
WHEN NOT MATCHED THEN INSERT (id, name) VALUES (s.id, s.name)

BigQuery

-- Backtick identifiers
SELECT * FROM `project.dataset.table`

-- UNNEST for array columns
SELECT * FROM `orders`, UNNEST(items) AS item

-- STRUCT access
SELECT address.city, address.state FROM customers

-- SAFE_DIVIDE to avoid division by zero
SELECT SAFE_DIVIDE(revenue, orders) AS avg_order_value FROM metrics

-- Timestamp handling
WHERE updated_at > TIMESTAMP({{lastExportDateTime}})

Redshift

-- PostgreSQL-based syntax
SELECT * FROM orders WHERE status = 'ACTIVE'

-- LISTAGG for string aggregation
SELECT customer_id, LISTAGG(product_name, ', ') WITHIN GROUP (ORDER BY product_name)
FROM order_items GROUP BY customer_id

-- bulk_load works on Redshift with no AWS setup (Celigo stages the files, Redshift loads them with COPY)

Pre-Submit Checklist

Export queries

  • SELECT query is syntactically valid for the target database dialect
  • Delta uses {{lastExportDateTime}} in the query, NOT a delta object inside rdbms -- double braces with no quotes of your own, and the export's top-level delta.startDate set so the first run isn't empty
  • Once export has both queries -- rdbms.query for SELECT and rdbms.once.query for UPDATE
  • Table and column names exist -- verify with celigo metadata types/fields <connectionId>
  • Snowflake uses fully qualified names -- database.schema.table unless the connection sets defaults

Import queries

  • query is an array of strings -- ["INSERT INTO ..."], not "INSERT INTO ..."
  • queryType is one value that fits the operation -- ["bulk_load"] on Snowflake, BigQuery, SQL Server (cloud connection), Azure Synapse, Redshift or NSAW, ["bulk_insert"] for pure INSERT, ["per_page"] or ["per_record"] for UPDATE/UPSERT elsewhere; never the legacy INSERT/UPDATE
  • bulkLoad.primaryKeys is an array -- ["ORDER_ID"], not "ORDER_ID"; set it for an upsert, with bulkLoad.tableName
  • All record. paths match incoming data -- invoke the upstream export to verify field names
  • Strings and dates use double braces, numbers and identifiers use triple -- {{record.name}} vs {{{record.id}}}
  • No quotes of your own around either form -- double braces already quote, and a hand-quoted '{{{record.name}}}' breaks on an apostrophe
  • Snowflake values that can hold a backslash, double quote or line break (JSON above all) use a dollar-quoted constant, $${{{...}}}$$, not double braces -- and only for data that can't contain $$ (gotcha 13)
  • Uses record. prefix -- not bare fieldName or data.fieldName
  • bulkInsert/bulkLoad not set alongside query -- these are mutually exclusive with the query field (except overrideMergeQuery)

Cross-resource

  • Connection takes SQL -- type is rdbms and rdbms.type names the database (mysql, mariadb, postgresql, mssql, azuresynapse, oracle, snowflake, bigquery, redshift). JDBC connections (type: "jdbc", with jdbc.type such as netsuitejdbc, db2, workday or databricks) also take SQL: exports in jdbc.query (plus jdbc.once.query for once exports), imports in jdbc.query according to jdbc.queryType
  • SQL dialect matches the database -- MERGE syntax differs between Snowflake, SQL Server, Oracle, PostgreSQL

Gotchas

  1. Double braces quote and escape in RDBMS. {{record.name}} outputs 'value' -- a SQL string literal with embedded quotes doubled (O'Neil Co becomes 'O''Neil Co'). {{{record.name}}} outputs value (raw). Use double braces for strings and dates with no quotes of your own, and triple braces for numbers and identifiers. Wrapping either in your own quotes breaks: '{{record.name}}' double-quotes the value, and '{{{record.name}}}' fails on the first apostrophe in the data.
  2. Import query must be an array. "query": "INSERT INTO ..." fails silently or throws a Cast error. Always use ["INSERT INTO ..."].
  3. queryType takes one value, fastest first. ["bulk_load"] where the database has it, ["bulk_insert"] for pure inserts, then ["per_page"], then ["per_record"] when the SQL can't be written for a page (step 2). Never combine values.
  4. Legacy queryType values are refused on every save. A create or update whose queryType holds INSERT (or the retired MERGE, COPY or BULK INSERT) fails with a 422 saying those query types are deprecated, on any database; a lowercase string such as insert fails as not a valid enum value. UPDATE is a legacy value too -- use per_record or per_page.
  5. An unresolvable reference fails the step. Query rendering is strict: a bare {{name}} (no record. prefix), or record.* when the arriving record is a grouped array (which binds rows instead), fails with cannot_evaluate_handlebars rather than rendering empty. Always use record.name, or rows.0.name / {{#each rows}} for grouped input.
  6. Snowflake requires fully qualified table names. database.schema.table unless the connection sets a default schema. Unqualified names fail silently or hit the wrong table.
  7. per_page has a different Handlebars context. The context is batch_of_records, not a single record. Use {{#each batch_of_records}}...{{record.fieldName}}...{{/each}}.
  8. bulkLoad.overrideMergeQuery references a staging table. Use {{import.rdbms.bulkLoad.preMergeTemporaryTable}} -- not the target table name.
  9. SQL Server MERGE requires a semicolon terminator. Missing ; at the end causes syntax errors.
  10. once.query runs per record, not per batch. The {{record.id}} in the once query refers to the current exported record. Don't write batch UPDATE statements here.
  11. Don't put delta config inside rdbms. There's no rdbms.delta property. Delta is handled by embedding {{lastExportDateTime}} directly in the SQL query text.
  12. NULL handling varies by dialect. Use NVL (Oracle), IFNULL (MySQL), COALESCE (standard/Snowflake/PostgreSQL/SQL Server). Don't assume one works everywhere.
  13. On Snowflake, a double-brace value with a backslash arrives changed. The quoting doubles apostrophes but leaves backslashes, and Snowflake reads them as escape sequences: C:\temp\new arrives with a tab and a line break in it, and no error is raised. For the same reason PARSE_JSON({{jsonSerialize record.payload}}) fails with 422 Error parsing JSON when a string in the payload holds a double quote or a line break (jsonSerialize escapes them with backslashes), and a backslash in the payload is changed. For values that can hold these characters -- JSON above all -- use a dollar-quoted constant with triple braces, which Snowflake reads as is: PARSE_JSON($${{{jsonSerialize record.payload}}}$$), or $${{{record.path}}}$$ for a string. A $$ in the data would end the constant, so keep this form to data that can't contain one.

Common Errors

Error Likely Cause Fix
Cast error or Invalid query format query is a string instead of an array Change to ["SQL here"]
cannot_evaluate_handlebars A reference the query can't resolve -- missing record. prefix, or record.* on a grouped record Use record.fieldName; for grouped input, rows.0.fieldName or {{#each rows}}
'42' instead of 42 for numeric field Double braces quote a number that arrives as a string ("42"); JSON numbers render bare Switch to triple braces {{{ }}}
''value'', or a syntax error at a quote Quotes added around a double-brace value, or a hand-quoted triple-brace value hit an apostrophe Use {{record.field}} with no quotes of your own
422 Error parsing JSON: missing comma or unterminated string (Snowflake PARSE_JSON) PARSE_JSON({{jsonSerialize ...}}) on data holding a double quote or line break: Snowflake reads the backslash escapes in the quoted literal PARSE_JSON($${{{jsonSerialize record.payload}}}$$) (gotcha 13)
Text in Snowflake lost its backslashes or gained tabs and line breaks (C:\temp arrives as C:, a tab, emp) A double-brace value holding backslashes A dollar-quoted constant, $${{{record.field}}}$$ (gotcha 13)
Compilation error: Object does not exist (Snowflake) Unqualified table name Use database.schema.table
422 Import query types "BULK INSERT", "INSERT", "MERGE", "COPY" are deprecated queryType holds a legacy value -- refused on every save, on any database Use per_record, per_page, bulk_insert or bulk_load
422 is not a valid enum value for path rdbms.queryType.0 A lowercase or unknown value such as insert Use one of per_record, per_page, first_page, bulk_insert, bulk_load
Merge statement must be terminated by ; (SQL Server) Missing semicolon at end of MERGE Add ; after the final clause
Ambiguous column reference JOIN without table alias Prefix columns with table aliases
Syntax error near ON DUPLICATE KEY Using MySQL syntax on PostgreSQL/Snowflake Use the correct dialect: ON CONFLICT (Postgres) or MERGE (Snowflake)
Column count doesn't match value count Mismatch between INSERT columns and VALUES Verify column list matches the number of record.x values
Permission denied for table Connection user lacks INSERT/UPDATE grants Check database permissions for the connection user