Error: Multi-part identifier "...." could not be boundSELECT payer_mstr.payer_name, CAST(YEAR(charges.zero_bal_date) AS char(4)) + '/' + CAST(MONTH(charges.zero_bal_date) AS varchar(2)) AS [YYYY/MM], CASE WHEN t_type = 'CH' THEN myunion.charges ELSE 0 END AS CHARGES, CASE WHEN t_type = 'A' THEN t_amt ELSE 0 END AS ADJUSTMENTS, CASE WHEN t_type = 'C' THEN t_amt ELSE 0 END AS PAYMENTS, CASE WHEN t_type = 'R' THEN t_amt ELSE 0 END AS REFUNDSFROM charges INNER JOIN payer_mstr INNER JOIN transactions ON payer_mstr.payer_id = transactions.payer_id INNER JOIN patient_encounter ON transactions.person_id = patient_encounter.person_id AND transactions.source_id = patient_encounter.enc_id ON charges.source_id = patient_encounter.enc_id AND charges.person_id = patient_encounter.person_id AND charges.source_id = transactions.source_id INNER JOIN (SELECT charges_2.source_id, charges_2.amt AS CHARGES, 'CH' AS t_type, 0 AS t_amt FROM charges AS charges_2 INNER JOIN payer_mstr AS payer_mstr_2 INNER JOIN transactions AS transactions_2 ON payer_mstr_2.payer_id = transactions_2.payer_id INNER JOIN patient_encounter AS patient_encounter_2 ON transactions_2.person_id = patient_encounter_2.person_id AND transactions_2.source_id = patient_encounter_2.enc_id ON charges_2.source_id = patient_encounter_2.enc_id AND charges_2.person_id = patient_encounter_2.person_id AND charges_2.source_id = transactions_2.source_id UNION SELECT charges.source_id, 0 AS CHARGES, transactions.type AS t_type, transactions.tran_amt AS t_amt FROM charges AS charges_1 INNER JOIN payer_mstr AS payer_mstr_1 INNER JOIN transactions AS transactions_1 ON payer_mstr_1.payer_id = transactions_1.payer_id INNER JOIN patient_encounter AS patient_encounter_1 ON transactions_1.person_id = patient_encounter_1.person_id AND transactions_1.source_id = patient_encounter_1.enc_id ON charges_1.source_id = patient_encounter_1.enc_id AND charges_1.person_id = patient_encounter_1.person_id AND charges_1.source_id = transactions_1.source_id) AS myunion ON charges.source_id = myunion.source_idWHERE (CAST(YEAR(charges.zero_bal_date) AS char(4)) + '/' + CAST(MONTH(charges.zero_bal_date) AS varchar(2)) > '2013/07')