Flyway generates invalid SQL when running multi-statement snowflake migrations with nested if statements.

[trainman]

Flyway fails to properly parse and execute the following sample repeatable migration. (Actual logic redacted and replaced with select statements.)

DECLARE 
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';

        IF (var_two) THEN
            SELECT 'Edge case 1' as truth;
        ELSE
            SELECT '...or edge case 2' as truth;
        END IF;

        SELECT 'Finish the work';
    END IF;
END;

SELECT 'Do the normal thing';

When a nested IF statement exists, this results in the 1st statement being incorrectly parsed by Flyway; as confirmed in the Flyway logs and Snowflake execution history.

Flyway Log:

[REDACTED]...
Nov 17, 2025 6:41:41 PM net.snowflake.client.core.SFSession open
INFO: Connecting to [REDACTED] Snowflake domain
Current version of schema "[REDACTED]": null
DEBUG: [REDACTED].sql ...
DEBUG: Found statement at line 1: DECLARE
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';

        IF (var_two) THEN
            SELECT 'Edge case 1' as truth;
        ELSE
            SELECT '...or edge case 2' as truth;
        END IF;

        SELECT 'Finish the work';
    END IF
DEBUG: Found statement at line 20: END
DEBUG: Found statement at line 22: SELECT 'Do the normal thing'
DEBUG: Starting migration of schema "[REDACTED]" with repeatable migration "[REDACTED]" ...
Migrating schema "[REDACTED]" with repeatable migration "[REDACTED]"
DEBUG: Executing SQL: DECLARE
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';

        IF (var_two) THEN
            SELECT 'Edge case 1' as truth;
        ELSE
            SELECT '...or edge case 2' as truth;
        END IF;

        SELECT 'Finish the work';
    END IF
DEBUG: Rolling back transaction...
DEBUG: Transaction rolled back
ERROR: Migration of schema "[REDACTED]" with repeatable migration "[REDACTED]" failed! Please restore backups and roll back database and code!
DEBUG: Schema History table "[REDACTED]"."flyway_schema_history" successfully updated to reflect changes
DEBUG: Memory usage: 64 of 95M
ERROR: Unexpected error
org.flywaydb.core.internal.exception.FlywayMigrateException: Failed to execute script [REDACTED].sql
------------------------------------------------------
SQL State  : 42000
Error Code : 1003
Message    : SQL compilation error:
syntax error line 19 at position 10 unexpected '<EOF>'.
Location   : tables/[REDACTED].sql ([REDACTED]/tables/[REDACTED].sql)
Line       : 1
Statement  : DECLARE
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';

        IF (var_two) THEN
            SELECT 'Edge case 1' as truth;
        ELSE
            SELECT '...or edge case 2' as truth;
        END IF;

        SELECT 'Finish the work';
    END IF

	at org.flywaydb.core.internal.command.DbMigrate.doMigrateGroup(DbMigrate.java:380)
	at org.flywaydb.core.internal.command.DbMigrate.lambda$applyMigrations$1(DbMigrate.java:264)
	at org.flywaydb.core.internal.jdbc.TransactionalExecutionTemplate.execute(TransactionalExecutionTemplate.java:40)
	at org.flywaydb.core.internal.command.DbMigrate.applyMigrations(DbMigrate.java:263)
	at org.flywaydb.core.internal.command.DbMigrate.migrateGroup(DbMigrate.java:236)
	at org.flywaydb.core.internal.command.DbMigrate.lambda$migrateAll$0(DbMigrate.java:134)
	at org.flywaydb.core.internal.jdbc.TableLockingExecutionTemplate$1.call(TableLockingExecutionTemplate.java:21)
	at org.flywaydb.core.internal.jdbc.TransactionalExecutionTemplate.execute(TransactionalExecutionTemplate.java:40)
	at org.flywaydb.core.internal.jdbc.TableLockingExecutionTemplate.execute(TableLockingExecutionTemplate.java:16)
	at org.flywaydb.core.internal.database.base.Connection.lock(Connection.java:87)
	at org.flywaydb.core.internal.schemahistory.JdbcTableSchemaHistory.lock(JdbcTableSchemaHistory.java:145)
	at org.flywaydb.core.internal.command.DbMigrate.migrateAll(DbMigrate.java:134)
	at org.flywaydb.core.internal.command.DbMigrate.migrate(DbMigrate.java:85)
	at org.flywaydb.core.Flyway.lambda$migrate$3(Flyway.java:227)
	at org.flywaydb.core.FlywayExecutor.execute(FlywayExecutor.java:215)
	at org.flywaydb.core.FlywayExecutor.execute(FlywayExecutor.java:99)
	at org.flywaydb.core.Flyway.migrate(Flyway.java:168)
	at org.flywaydb.commandline.Main.executeOperation(Main.java:286)
	at org.flywaydb.commandline.Main.executeFlyway(Main.java:192)
	at org.flywaydb.commandline.Main.main(Main.java:119)
Caused by: org.flywaydb.core.internal.sqlscript.FlywaySqlScriptException: Failed to execute script [REDACTED].sql
------------------------------------------------------
SQL State  : 42000
Error Code : 1003
Message    : SQL compilation error:
syntax error line 19 at position 10 unexpected '<EOF>'.
Location   : tables/[REDACTED].sql ([REDACTED]/tables/[REDACTED].sql)
Line       : 1
Statement  : DECLARE
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';

        IF (var_two) THEN
            SELECT 'Edge case 1' as truth;
        ELSE
            SELECT '...or edge case 2' as truth;
        END IF;

        SELECT 'Finish the work';
    END IF

	at org.flywaydb.core.internal.sqlscript.DefaultSqlScriptExecutor.handleException(DefaultSqlScriptExecutor.java:232)
	at org.flywaydb.core.internal.sqlscript.DefaultSqlScriptExecutor.executeStatement(DefaultSqlScriptExecutor.java:193)
	at org.flywaydb.core.internal.sqlscript.DefaultSqlScriptExecutor.execute(DefaultSqlScriptExecutor.java:115)
	at org.flywaydb.core.internal.resolver.sql.SqlMigrationExecutor.executeOnce(SqlMigrationExecutor.java:56)
	at org.flywaydb.core.internal.resolver.sql.SqlMigrationExecutor.lambda$execute$0(SqlMigrationExecutor.java:47)
	at org.flywaydb.core.internal.database.DefaultExecutionStrategy.execute(DefaultExecutionStrategy.java:12)
	at org.flywaydb.core.internal.resolver.sql.SqlMigrationExecutor.execute(SqlMigrationExecutor.java:46)
	at org.flywaydb.core.internal.command.DbMigrate.doMigrateGroup(DbMigrate.java:372)
	... 19 more
Caused by: net.snowflake.client.jdbc.SnowflakeSQLException: SQL compilation error:
syntax error line 19 at position 10 unexpected '<EOF>'.
	at net.snowflake.client.jdbc.SnowflakeUtil.checkErrorAndThrowExceptionSub(SnowflakeUtil.java:188)
	at net.snowflake.client.jdbc.SnowflakeUtil.checkErrorAndThrowException(SnowflakeUtil.java:120)
	at net.snowflake.client.core.StmtUtil.pollForOutput(StmtUtil.java:511)
	at net.snowflake.client.core.StmtUtil.execute(StmtUtil.java:416)
	at net.snowflake.client.core.SFStatement.executeHelper(SFStatement.java:502)
	at net.snowflake.client.core.SFStatement.executeQueryInternal(SFStatement.java:211)
	at net.snowflake.client.core.SFStatement.executeQuery(SFStatement.java:145)
	at net.snowflake.client.core.SFStatement.execute(SFStatement.java:779)
	at net.snowflake.client.core.SFStatement.execute(SFStatement.java:697)
	at net.snowflake.client.jdbc.SnowflakeStatementV1.executeInternal(SnowflakeStatementV1.java:350)
	at net.snowflake.client.jdbc.SnowflakeStatementV1.execute(SnowflakeStatementV1.java:425)
	at org.flywaydb.core.internal.jdbc.JdbcTemplate.executeStatement(JdbcTemplate.java:196)
	at org.flywaydb.core.internal.sqlscript.ParsedSqlStatement.execute(ParsedSqlStatement.java:69)
	at org.flywaydb.core.internal.sqlscript.DefaultSqlScriptExecutor.executeStatement(DefaultSqlScriptExecutor.java:188)
	... 25 more
...[REDACTED]

Logged Snowflake Query History

DECLARE 
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';

        IF (var_two) THEN
            SELECT 'Edge case 1' as truth;
        ELSE
            SELECT '...or edge case 2' as truth;
        END IF;

        SELECT 'Finish the work';
    END IF

Expected 1st statement (note the ";" at the end of "end if" and the "END;" for the declare block were both missing in the query executed by Flyway.)

DECLARE 
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';

        IF (var_two) THEN
            SELECT 'Edge case 1' as truth;
        ELSE
            SELECT '...or edge case 2' as truth;
        END IF;

        SELECT 'Finish the work';
    END IF;
END;

[trainman]

Attempting to unroll the nested IF, into a series of sequential if statements failed in the same method.

Ex:

DECLARE 
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';
    END IF;
    
    IF (var_one and var_two) THEN
        SELECT 'Edge case 1' as truth;
    ELSE
        SELECT '...or edge case 2' as truth;
    END IF;

    IF (var_one) THEN
        SELECT 'Finish the work';
    END IF;
END;

Attempted to execute: (It completely cut off everything from the semi colon of the 2nd if statement.)

DECLARE 
    var_one BOOLEAN;
    var_two BOOLEAN;
BEGIN
    SELECT sysdate() > '1900-01-01' INTO var_one;

    IF (var_one) THEN
        SELECT sysdate() < '1900-01-01' INTO var_two;

        SELECT 'Due to var_one, we need to handle edge cases before we continue';
    END IF;
    
    IF (var_one and var_two) THEN
        SELECT 'Edge case 1' as truth;
    ELSE
        SELECT '...or edge case 2' as truth;
    END IF

Per Snowflake's documentation, IF statements must end in a semi colon.
https://docs.snowflake.com/en/sql-reference/snowflake-scripting/if