Schema and data diff

Both tools compare two open SQL connections, which can be different engines. Open the second connection first, then use the Create… menu in the sidebar.

Schema diff

Diff schema with another connection…: pick the Source, the Target and the Schema, then Compare.

Lily compares tables, columns, column types and nullability, and lists:

• tables only in the source;
• tables only in the target;
• changed tables, with added and removed columns and type changes.

Indexes, keys and defaults are not compared.

Generate sync DDL writes a script that brings the target closer to the source: CREATE TABLE for missing tables and ADD COLUMN for missing columns. Type changes and anything that exists only in the target are written as comments for you to decide. Lily never runs the script; copy it into a query tab and review it there. Types are copied as they are, so check them when the engines differ.

Data diff

Diff data with another connection…: pick the source, target, schema and a table that exists on both sides, then Compare.

Rows are matched by the source table's primary key (without one, Lily matches whole rows and tells you so). The result counts rows only in the source, only in the target, changed and identical, and lists the changed ones column by column.

Lily compares up to 5,000 rows per side, as text, using the columns both tables share. The data diff only reports; it does not write a sync script.