select max(case when a>1 then 1 else 0 end),max(case when b>1 then 1 else 0 end) from table这个

SQL查询语句使用了两个聚合函数MAX和CASE WHEN语句。

该查询语句从名为table的表中选择两列，然后将每列的最大值计算为1或0，具体取决于该列中的每个值是否大于1。对于第一列，如果a大于1，则将其计算为1，否则计算为0。对于第二列，如果b大于1，则将其计算为1，否则计算为0。最后，查询返回两个最大值，一个是第一列的最大值，另一个是第二列的最大值。

相关问题

你能把pg视图改为sqlserver的视图吗 SELECT c.relname AS table_name, a.attname AS column_name, d.description AS column_comment, CASE WHEN a.attnotnull AND con.conname IS NULL THEN 1 ELSE 0 END AS is_required, CASE WHEN con.conname IS NOT NULL THEN 1 ELSE 0 END AS is_pk, a.attnum AS sort, CASE WHEN "position"(pg_get_expr(ad.adbin, ad.adrelid), ((c.relname::text || '_'::text) || a.attname::text) || '_seq'::text) > 0 THEN 1 ELSE 0 END AS is_increment, btrim( CASE WHEN t.typelem <> 0::oid AND t.typlen = '-1'::integer THEN 'ARRAY'::text ELSE CASE WHEN t.typtype = 'd'::"char" THEN format_type(t.typbasetype, NULL::integer) ELSE format_type(a.atttypid, NULL::integer) END END, '"'::text) AS column_type FROM pg_attribute a JOIN (pg_class c JOIN pg_namespace n ON c.relnamespace = n.oid) ON a.attrelid = c.oid LEFT JOIN pg_description d ON d.objoid = c.oid AND a.attnum = d.objsubid LEFT JOIN pg_constraint con ON con.conrelid = c.oid AND (a.attnum = ANY (con.conkey)) LEFT JOIN pg_attrdef ad ON a.attrelid = ad.adrelid AND a.attnum = ad.adnum LEFT JOIN pg_type t ON a.atttypid = t.oid WHERE (c.relkind = ANY (ARRAY['r'::"char", 'p'::"char"])) AND a.attnum > 0 AND n.nspname = 'public'::name ORDER BY c.relname, a.attnum

抱歉，我无法将此查询转换为SQL Server的视图。这是因为该查询涉及到了一些PostgreSQL特定的函数和表达式，这些在SQL Server中并不存在。你可能需要手动重新编写查询以适应SQL Server的语法和函数。以下是一个可能的SQL Server等效查询的示例，供参考：

SELECT 
    t.name AS table_name,
    c.name AS column_name,
    CAST(ep.value AS NVARCHAR(MAX)) AS column_comment,
    CASE
        WHEN c.is_nullable = 0 AND pk.constraint_column_id IS NULL THEN 1
        ELSE 0
    END AS is_required,
    CASE
        WHEN pk.constraint_column_id IS NOT NULL THEN 1
        ELSE 0
    END AS is_pk,
    c.column_id AS sort,
    CASE
        WHEN COLUMNPROPERTY(c.object_id, c.name, 'IsIdentity') = 1 THEN 1
        ELSE 0
    END AS is_increment,
    CASE
        WHEN t.name = 'varchar' AND c.max_length <> -1 THEN t.name + '(' + CAST(c.max_length AS NVARCHAR(MAX)) + ')'
        WHEN t.name = 'nvarchar' AND c.max_length <> -1 THEN t.name + '(' + CAST(c.max_length / 2 AS NVARCHAR(MAX)) + ')'
        ELSE t.name
    END AS column_type
FROM sys.tables t
INNER JOIN sys.columns c ON t.object_id = c.object_id
LEFT JOIN sys.extended_properties ep ON ep.major_id = t.object_id AND ep.minor_id = c.column_id AND ep.name = 'MS_Description'
LEFT JOIN sys.indexes i ON t.object_id = i.object_id AND i.is_primary_key = 1
LEFT JOIN sys.index_columns ic ON i.object_id = ic.object_id AND i.index_id = ic.index_id AND c.column_id = ic.column_id
LEFT JOIN sys.key_constraints pk ON t.object_id = pk.parent_object_id AND ic.index_column_id = pk.unique_index_id
WHERE t.type = 'U'
AND SCHEMA_NAME(t.schema_id) = 'dbo'
ORDER BY t.name, c.column_id

请注意，这只是一个示例查询，具体取决于你的数据库结构和需求，你可能需要进行一些调整和修改。建议在转换之前备份你的数据库，以防出现意外情况。

SELECT t1.id, STUFF((SELECT ',' + CONVERT(VARCHAR, CASE WHEN ISNUMERIC(REPLACE(t2.hsdj, ',', '')) = 1 THEN CAST(REPLACE(t2.hsdj, ',', '') AS FLOAT) ELSE NULL END) FROM formtable_main_43_dt1 t2 WHERE t1.id = t2.mainid FOR XML PATH ('')), 1, 1, '') AS MergedValues, STUFF((SELECT ',' + CAST(CAST(t1.htwj AS VARBINARY(MAX)) AS VARCHAR(MAX)) FROM formtable_main_43 t1 WHERE t1.id = t2.mainid FOR XML PATH ('')), 1, 1, '') AS ImageValues FROM formtable_main_43 t1 INNER JOIN formtable_main_43_dt1 t2 ON t1.id = t2.mainid GROUP BY t1.id t1.htwj;提示“t1”附近有语法错误

根据你提供的 SQL 语句，应该是这个部分出现了问题：

SELECT t1.id, STUFF((SELECT ',' + CONVERT(VARCHAR, CASE WHEN ISNUMERIC(REPLACE(t2.hsdj, ',', '')) = 1 THEN CAST(REPLACE(t2.hsdj, ',', '') AS FLOAT) ELSE NULL END) FROM formtable_main_43_dt1 t2 WHERE t1.id = t2.mainid FOR XML PATH ('')), 1, 1, '') AS MergedValues, STUFF((SELECT ',' + CAST(CAST(t1.htwj AS VARBINARY(MAX)) AS VARCHAR(MAX)) FROM formtable_main_43 t1  WHERE t1.id = t2.mainid FOR XML PATH ('')), 1, 1, '') AS ImageValues FROM formtable_main_43 t1 INNER JOIN formtable_main_43_dt1 t2 ON t1.id = t2.mainid  GROUP BY t1.id t1.htwj;

在 GROUP BY 子句中，应该使用逗号将分组的列分隔开，而不是空格。所以你需要将 `GROUP BY t1.id t1.htwj` 改为 `GROUP BY t1.id, t1.htwj`。