Oracle查詢今天、昨天、本周、上周、本月、上月數據

查詢今天數據：

SELECT COUNT(1) FROM T_CALL_RECORDS WHERE TO_CHAR(T_RKSJ,'YYYY-MM-DD')=TO_CHAR(SYSDATE,'YYYY-MM-DD')
查詢昨天數據：

SELECT COUNT(1) FROM T_CALL_RECORDS WHERE TO_CHAR(T_RKSJ,'YYYY-MM-DD')=TO_CHAR(SYSDATE-1,'YYYY-MM-DD') 
查詢本周數據：

SELECT COUNT(1) FROM T_CALL_RECORDS WHERE T_RKSJ >= TRUNC(NEXT_DAY(SYSDATE-8,1)+1) AND T_RKSJ < TRUNC(NEXT_DAY(SYSDATE-8,1)+7)+1
查詢上周數據：

SELECT COUNT(1) FROM T_CALL_RECORDS WHERE T_RKSJ >= TRUNC(NEXT_DAY(SYSDATE-8,1)-6) AND T_RKSJ < TRUNC(NEXT_DAY(SYSDATE-8,1)+1)
查詢本月數據：

SELECT COUNT(1) FROM T_CALL_RECORDS WHERE TO_CHAR(T_RKSJ,'YYYY-MM')=TO_CHAR(SYSDATE,'YYYY-MM')
查詢上月數據：

SELECT COUNT(1) FROM T_CALL_RECORDS WHERE TO_CHAR(T_RKSJ,'YYYY-MM')=TO_CHAR(ADD_MONTHS(SYSDATE,-1),'YYYY-MM')
查詢表名及字段信息數據：

SELECT A.TABLE_NAME 表名,A.COLUMN_NAME 字段名,A.COMMENTS 字段注釋,B.DATA_TYPE 字段類型,B.DATA_LENGTH 字段長度,B.NULLABLE 是否為空,C.INDEX_NAME 索引名稱
FROM USER_COL_COMMENTS A 
LEFT JOIN USER_TAB_COLUMNS B ON A.COLUMN_NAME = B.COLUMN_NAME AND A.TABLE_NAME=B.TABLE_NAME
LEFT JOIN USER_IND_COLUMNS C ON A.COLUMN_NAME = C.COLUMN_NAME AND A.TABLE_NAME=C.TABLE_NAME 
WHERE A.TABLE_NAME = '表名'
ORDER BY B.COLUMN_ID