sql-timestamp

问题 In my application running on Java 8, I have a Date object. The timezone for this object depends on the client's location. At one particular point, I need to convert this Date to GMT so that it could be comparable to a value that I access from the DB. I tried SimpleDateFormat and ZonedDateTime, but there's a pain-point. These API's provide me GMT time in String values, which is perfectly fine. However, once I parse it and assign it to a Date object, it is back to my local timezone! For Ex:

问题 In my application running on Java 8, I have a Date object. The timezone for this object depends on the client's location. At one particular point, I need to convert this Date to GMT so that it could be comparable to a value that I access from the DB. I tried SimpleDateFormat and ZonedDateTime, but there's a pain-point. These API's provide me GMT time in String values, which is perfectly fine. However, once I parse it and assign it to a Date object, it is back to my local timezone! For Ex:

问题 I have a postgresql table as CREATE TABLE IF NOT EXISTS table_name ( expiry_date DATE NOT NULL, created_at TIMESTAMP with time zone NOT NULL DEFAULT CURRENT_TIMESTAMP(0), CONSTRAINT user_review_uniq_key UNIQUE (expiry_date, created_at::date) -- my wrong attempt of using :: ) I want to put uniue constraint on this table in such a way that expiry_date and date of created_at should be unique. Problem is created_at column is timestamp not date. so is there any way to put unique constraint such

问题 I am trying to write a report based on data of users logging into a session. I need to be able to get a full session time from when the first person joins the meeting to when the last person leaves. When someone joins a meeting it is logged as, "Initialize-Load Video chat Window" There are 2 ways to close the meeting but one way is being logged. - There is an "End Chat" button that the user can use and that is logged as, "Video Chat-End Chat" - If the user does not use that button and just

问题 I have a table called visit_times in SQL like this name time_stamp Allen 2015-02-13 07:10:54 Allen 2015-02-13 07:10:58 Allen 2015-02-13 07:11:02 Mary 2015-02-17 10:45:33 Mary 2015-02-17 10:45:39 Mary 2015-02-17 10:45:43 ... I need to select names from "name" column for which all the row-consecutive differences (in second) in the "time_stamp" column equals a certain value. Using the LAG() command I have tried to code it up as follows WITH cte AS ( SELECT name, DATEDIFF(second, LAG(time_stamp)

问题 I have a table called visit_times in SQL like this name time_stamp Allen 2015-02-13 07:10:54 Allen 2015-02-13 07:10:58 Allen 2015-02-13 07:11:02 Mary 2015-02-17 10:45:33 Mary 2015-02-17 10:45:39 Mary 2015-02-17 10:45:43 ... I need to select names from "name" column for which all the row-consecutive differences (in second) in the "time_stamp" column equals a certain value. Using the LAG() command I have tried to code it up as follows WITH cte AS ( SELECT name, DATEDIFF(second, LAG(time_stamp)

问题 I have a table called visit_times in SQL like this name time_stamp Allen 2015-02-13 07:10:54 Allen 2015-02-13 07:10:58 Allen 2015-02-13 07:11:02 Mary 2015-02-17 10:45:33 Mary 2015-02-17 10:45:39 Mary 2015-02-17 10:45:43 ... I need to select names from "name" column for which all the row-consecutive differences (in second) in the "time_stamp" column equals a certain value. Using the LAG() command I have tried to code it up as follows WITH cte AS ( SELECT name, DATEDIFF(second, LAG(time_stamp)

问题 I am using SqlAlchemy on python3.4.3 to manage a MySQL database. I was creating a table with: from datetime import datetime from sqlalchemy import Column, text, create_engine from sqlalchemy.types import TIMESTAMP from sqlalchemy.dialects.mysql import BIGINT from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class MyClass(Base): __tablename__ = 'my_class' id = Column(BIGINT(unsigned=True), primary_key=True) created_at = Column(TIMESTAMP, default=datetime.utcnow,

问题 I am using SqlAlchemy on python3.4.3 to manage a MySQL database. I was creating a table with: from datetime import datetime from sqlalchemy import Column, text, create_engine from sqlalchemy.types import TIMESTAMP from sqlalchemy.dialects.mysql import BIGINT from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class MyClass(Base): __tablename__ = 'my_class' id = Column(BIGINT(unsigned=True), primary_key=True) created_at = Column(TIMESTAMP, default=datetime.utcnow,

问题 I am using SqlAlchemy on python3.4.3 to manage a MySQL database. I was creating a table with: from datetime import datetime from sqlalchemy import Column, text, create_engine from sqlalchemy.types import TIMESTAMP from sqlalchemy.dialects.mysql import BIGINT from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class MyClass(Base): __tablename__ = 'my_class' id = Column(BIGINT(unsigned=True), primary_key=True) created_at = Column(TIMESTAMP, default=datetime.utcnow,