From what I can understand, apart from a Customer table, you'll need three tables:

1. Contract — holding the single-valued data about a contract, excluding receipts. It might record the latest receipt number for the contract, but that would be an optimization, storing derivable data.
2. Contract Items — holding the 1-6 items for the contract.
3. Receipts — holding information about receipts.

A given receipt is associated with one contract; a single contract may have multiple receipts over time if it is a pawn contract (buy and sell contracts will have a single receipt).

Even if a new receipt is not issued when a pawn contract is cancelled, there'll need to be a database update of the contract or the receipt (or both) to indicate that the contract is cancelled.

Is there anything that I'm missing here?

From what I can understand, apart from a Customer table, you'll need three tables:

1. Contract — holding the single-valued data about a contract, excluding receipts. It might record the latest receipt number for the contract, but that would be an optimization, storing derivable data. Primary Key: Contract Number (aka Lot Number).
2. Contract Items — holding the 1-6 items for the contract. Primary Key: Lot Number, Lot Sequence Number. Lot Number is a Foreign Key reference to Contract.
3. Receipts — holding information about receipts. Primary Key: Receipt Number. Foreign Key: Contract Number reference to Contract again.

A given receipt is associated with one contract; a single contract may have multiple receipts over time if it is a pawn contract (buy and sell contracts will have a single receipt).

Even if a new receipt is not issued when a pawn contract is cancelled, there'll need to be a database update of the contract or the receipt (or both) to indicate that the contract is cancelled.

Is there anything that I'm missing here?

From what I can understand, apart from a Customer table, you'll need three tables:

1. Contract — holding the single-valued data about a contract, excluding receipts.
2. Contract Items — holding the 1-6 items for the contract.
3. Receipts — holding information about receipts.

A given receipt is associated with one contract; a single contract may have multiple receipts over time if it is a pawn contract (buy and sell contracts will have a single receipt).

Even if a new receipt is not issued when a pawn contract is cancelled, there'll need to be a database update of the contract or the receipt (or both) to indicate that the contract is cancelled.

Is there anything that I'm missing here?

From what I can understand, apart from a Customer table, you'll need three tables:

1. Contract — holding the single-valued data about a contract, excluding receipts. It might record the latest receipt number for the contract, but that would be an optimization, storing derivable data.
2. Contract Items — holding the 1-6 items for the contract.
3. Receipts — holding information about receipts.

A given receipt is associated with one contract; a single contract may have multiple receipts over time if it is a pawn contract (buy and sell contracts will have a single receipt).

Even if a new receipt is not issued when a pawn contract is cancelled, there'll need to be a database update of the contract or the receipt (or both) to indicate that the contract is cancelled.

Is there anything that I'm missing here?