Table and column capitalization

When working with CARTO, how your table and column names are handled depends on two factors: your data warehouse provider and how you access the data.

How you access data matters

Access method	How identifiers are handled
Table sources (Data Explorer, Builder table source, Workflows)	CARTO handles quoting automatically, but has limitations with non-standard names
SQL Query sources (Builder SQL editor)	You control quoting — full flexibility but requires knowledge of provider rules

Provider-specific rules

Each data warehouse treats unquoted identifiers differently:

Provider	Default behavior	Quote character
BigQuery	Case-sensitive (unchanged)	` (backticks)
Snowflake	Converted to UPPERCASE	" (double quotes)
PostgreSQL	Converted to lowercase	" (double quotes)
Redshift	Converted to lowercase	" (double quotes)
Databricks	Case-insensitive	` (backticks)

Known limitations with table sources

When loading tables in Data Explorer, Builder (table source), or Workflows, certain column naming patterns are not fully supported.

Unsupported patterns

Provider	Unsupported pattern	Example	Workaround
Snowflake	Lowercase column names (created with quotes)	"myColumn", "revenue"	Use SQL Query source, or rename columns to UPPERCASE
PostgreSQL	Uppercase column names (created with quotes)	"MyColumn", "Revenue"	Use SQL Query source, or rename columns to lowercase
All providers	Columns with special characters	my-column, my column	Use SQL Query source, or rename columns
All providers	SQL reserved words as column names	select, from, where	Use SQL Query source, or rename columns

Why this happens: When you create a column with quotes in your warehouse (e.g., "myColumn" in Snowflake), the warehouse preserves that exact casing. However, when CARTO builds queries for table sources, it may not apply the required quoting for these edge cases.

Using SQL Query sources

SQL Query sources give you full control over identifier quoting. Use the appropriate quote character for your warehouse:

Snowflake

Double quotes preserve lowercase or mixed case:

SELECT "myColumn", "Revenue_2024" FROM "MySchema"."SalesData"

PostgreSQL and Redshift

Double quotes preserve uppercase or mixed case:

SELECT "MyColumn", "Revenue_2024" FROM "public"."SalesData"

BigQuery

Backticks for all identifiers; case is always preserved:

SELECT myColumn, Revenue_2024 FROM `project.dataset.SalesData`

Databricks

Backticks for special characters; case doesn't matter:

SELECT myColumn FROM `my-catalog`.schema.sales_data

Best practices

To ensure compatibility across all CARTO features, use naming conventions that match your provider's default behavior:

Recommended naming conventions

Provider	Recommended naming
Snowflake	UPPERCASE or UPPER_SNAKE_CASE
PostgreSQL / Redshift	lowercase or snake_case
BigQuery	Any consistent style (case-sensitive)
Databricks	Any style (snake_case recommended)

General guidelines:

• Use snake_case with letters matching your provider's default (uppercase for Snowflake, lowercase for PostgreSQL)

• Avoid spaces, hyphens, and special characters in names

• Avoid SQL reserved words (select, from, where, order, group, etc.)

• If you must use non-standard names, access the data via SQL Query source

Troubleshooting

Error	Likely cause	Solution
"Column not found" in Snowflake	Column was created with lowercase (quoted)	Use SQL Query source with proper quoting: "myColumn"
"Column does not exist" in PostgreSQL	Column was created with uppercase (quoted)	Use SQL Query source with proper quoting: "MyColumn"
Table loads but some columns missing	Column names use reserved words or special characters	Use SQL Query source
Works in warehouse console, fails in CARTO table view	Non-standard identifier naming	Use SQL Query source instead