在BigQuery中，可以使用UNNEST函数来解决不平等连接的问题。以下是一个示例代码，演示了如何避免不平等连接：

WITH
  table1 AS (
  SELECT
    1 AS id,
    ['A', 'B', 'C'] AS letters
  UNION ALL
  SELECT
    2 AS id,
    ['D', 'E'] AS letters ),
  table2 AS (
  SELECT
    'A' AS letter,
    'Alpha' AS name
  UNION ALL
  SELECT
    'B' AS letter,
    'Beta' AS name
  UNION ALL
  SELECT
    'C' AS letter,
    'Gamma' AS name
  UNION ALL
  SELECT
    'D' AS letter,
    'Delta' AS name
  UNION ALL
  SELECT
    'E' AS letter,
    'Epsilon' AS name )
SELECT
  table1.id,
  letter,
  name
FROM
  table1,
  UNNEST(table1.letters) AS letter
LEFT JOIN
  table2
ON
  letter = table2.letter

在这个示例中，我们有两个表：table1和table2。table1包含了一个id字段和一个letters数组字段，table2包含了一个letter字段和一个name字段。

在查询中，我们使用了UNNEST函数来将table1中的letters数组展开成单个的letter值。然后，我们使用LEFT JOIN来将展开的letter值与table2中的letter字段进行连接。

这样，我们就可以避免不平等连接的问题，同时可以获取到正确的连接结果。