convert

Transform SQL dumps between different database dialects.

Alias: cv (e.g., sql-splitter cv mysql.sql --to postgres -o pg.sql)

When to Use This

• Database migration - Moving from MySQL to PostgreSQL (or any other combination)
• Cross-platform development - Convert production dumps to SQLite for local testing
• Cloud migration - Transform on-premise SQL Server dumps for cloud PostgreSQL
• Tool compatibility - Convert between dialects when tools only support specific formats

Use validate after conversion to verify the output is valid for your target database.

How It Works

The converter parses the source dump, transforms DDL (CREATE TABLE, indexes, constraints) and DML (INSERT, COPY) statements to the target dialect. This includes:

• Identifier quoting - Backticks (MySQL) ↔ double quotes (PostgreSQL/SQLite) ↔ brackets (MSSQL)
• Data types - Maps 50+ types between dialects (e.g., AUTO_INCREMENT → SERIAL)
• Bulk import syntax - Converts PostgreSQL COPY ... FROM stdin to INSERT statements for other dialects
• String escaping - Adapts escape sequences between dialects

Usage

sql-splitter convert <INPUT> --to <DIALECT> [OPTIONS]

Examples

Basic Conversion

# MySQL to PostgreSQL
sql-splitter convert mysql.sql --to postgres -o pg.sql

# PostgreSQL to MySQL (COPY blocks become INSERT statements)
sql-splitter convert pg_dump.sql --to mysql -o mysql.sql

# Any dialect to SQLite (great for local development)
sql-splitter convert dump.sql --to sqlite -o sqlite.sql

Explicit Source Dialect

Auto-detection works in most cases, but you can specify the source explicitly:

# When auto-detection fails or you want to be explicit
sql-splitter convert dump.sql --from mssql --to mysql -o mysql.sql

Strict Mode for CI/CD

Use --strict to fail on any unsupported features instead of emitting warnings:

sql-splitter convert dump.sql --to postgres --strict

Streaming Directly to Database

Pipe the converted output directly into your database client:

# Convert and restore in one step
sql-splitter convert mysql.sql.gz --to postgres -o - | psql "$PG_CONN"

# Convert and load into SQLite
sql-splitter convert pg_dump.sql --to sqlite -o - | sqlite3 dev.db

Options

Flag	Short	Description	Default
--output	-o	Output SQL file or directory	stdout
--from		Source dialect: mysql, postgres, sqlite, mssql	auto-detect
--to		Target dialect (required)	-
--strict		Fail on any unsupported feature	false
--progress	-p	Show progress bar	false
--dry-run		Preview without writing files	false
--fail-fast		Stop on first error (for glob patterns)	false
--json		Output results as JSON	false

Supported Conversions

All 12 conversion pairs are supported:

• MySQL ↔ PostgreSQL (including COPY → INSERT)
• MySQL ↔ SQLite
• MySQL ↔ MSSQL
• PostgreSQL ↔ SQLite
• PostgreSQL ↔ MSSQL
• SQLite ↔ MSSQL

Type Mappings

50+ data type mappings are handled automatically:

MySQL	PostgreSQL	SQLite	MSSQL
INT AUTO_INCREMENT	SERIAL	INTEGER PRIMARY KEY	INT IDENTITY
TINYINT(1)	BOOLEAN	INTEGER	BIT
VARCHAR(n)	VARCHAR(n)	TEXT	NVARCHAR(n)
DATETIME	TIMESTAMP	TEXT	DATETIME2
TEXT	TEXT	TEXT	NVARCHAR(MAX)
BLOB	BYTEA	BLOB	VARBINARY(MAX)

PostgreSQL COPY Conversion

PostgreSQL’s COPY ... FROM stdin format is converted to INSERT statements:

-- Input (PostgreSQL)
COPY users (id, name) FROM stdin;
1  Alice
2  Bob
\.

-- Output (MySQL)
INSERT INTO users (id, name) VALUES (1, 'Alice');
INSERT INTO users (id, name) VALUES (2, 'Bob');

Warnings and Unsupported Features

The conversion continues successfully even when encountering unsupported features - they generate warnings but don’t stop the process.

Features that are converted with warnings

These types are converted to the closest equivalent, with a warning:

Feature	Converted To	Notes
MySQL ENUM('a','b','c')	VARCHAR(255) (PostgreSQL/MSSQL) or TEXT (SQLite)	Enum values are lost; consider adding CHECK constraints manually
PostgreSQL arrays (INT[])	JSON (MySQL), TEXT (SQLite), NVARCHAR(MAX) (MSSQL)	Data format preserved as JSON string

Features that are skipped entirely

These statements are omitted from the output (with a warning):

• CREATE TRIGGER - Trigger syntax is too dialect-specific to convert
• CREATE PROCEDURE / CREATE FUNCTION - Stored procedure logic cannot be automatically translated
• CREATE TYPE - Custom types have no equivalent in most dialects
• CREATE DOMAIN - PostgreSQL-specific
• CREATE EXTENSION - PostgreSQL-specific
• CREATE SEQUENCE - Skipped because SERIAL/BIGSERIAL columns are converted to AUTO_INCREMENT/IDENTITY, which handle sequencing automatically
• COMMENT ON - Not supported in all dialects

The command outputs a count of skipped statements at the end. Use --strict to fail instead of skipping.

See Type Mappings Reference for the complete list of 50+ type conversions.

Troubleshooting

Conversion fails on specific statements

If conversion fails completely (not just warnings), check:

1. Syntax errors in source dump - Validate first: sql-splitter validate dump.sql
2. Wrong source dialect detected - Specify explicitly: --from mysql
3. Malformed statements - The error message includes the problematic statement

Output differs between runs

The converter preserves statement order from the input. If your dump has non-deterministic ordering (e.g., mysqldump without --order-by-primary, or tables listed in different order each time):

# Sort the dump first for stable, reproducible output
sql-splitter order dump.sql -o ordered.sql
sql-splitter convert ordered.sql --to postgres -o pg.sql

This is especially important for CI where you want to detect actual changes, not ordering noise.

Wrong dialect auto-detected

Force the source dialect explicitly:

sql-splitter convert ambiguous.sql --from mysql --to postgres -o pg.sql

Converted dump fails to import

1. Validate the output: sql-splitter validate pg.sql --dialect postgres
2. Check for unsupported features: Re-run with --strict to see all warnings
3. Check type mappings: See Type Mappings Reference for dialect-specific details

See Also

• validate - Validate converted output
• Dialect Reference - Detailed dialect information
• Type Mappings Reference - Data type conversion details
• JSON Output Schema - Schema for --json output