The syntax of the WHERE statement in SQL

update Table 1 set field 1='New value'where Time field 1>='Start time'and time field 1<='End time'

Upstairs, your statement is not right, in SQL Server the SQL statement date type field is also enclosed in single quotation marks, in the access database in the date type field format should be written as " date", so according to the different database system The representation is also a little different.

As for the landlord's problem, you can use the update statement to update the record over a period of time, as the second floor said.

select * from [**] where Time parameter ='Start time'and time parameter <='End time'

It is recommended that the date field in the database be used as a string, which will be easier to handle, and the two upstairs are the strings.

The first way to write it is correct.

Of course, if you have more conditions, you can also add (), for example: select fromtbwhere(a field x ora field y) andb field zzz.

Structured Query Language (SQL), abbreviated as SQL, is a special-purpose programming language that is a database query and programming language used to access data and query, update, and manage relational database systems. SQL uses single quotes to wrap text values (most database systems also accept double quotes).

Text value: This is correct: select frompersonswherefirstname bush.

This is wrong: select frompersonswherefirstname bush.

1. where is used as a subordinate conjunction, which can lead the place adverbial clause, equivalent to in at, to the place, and its former friends bury the words that strengthen the tone, such as just, only, even, right, etc. or the negative word not, sometimes some components can be omitted.

2. where can also lead to a contrasting adverbial clause, which is equivalent to while, which can be translated as "while, but, and vice versa".

3. WHERE can also guide the concession adverbial clause, the tone is lighter, and the inverted form is often used in the clause.

4. where can also guide the surface liquid royal clause, and the antecedent in front of it is often omitted.

1.The basic usage of where.

Where is a commonly used word in English to express "**", often used to inquire about, and describe a place. Sun Crack for example:

where are you from?(You're from?) ）

i'm going to the park. do you know where it is?(I went to the park.) Did you know it's in **? ）

this is where i live.(That's where I live.) ）

2.Extended usage of where.

In addition to the basic place inquiry and description, there are some extended uses of where, such as:

wh- be preposition curvature where, means "in what place" or "in which place". For example: where is the cocktail party?

it's at the bar.(Cocktail party at **?) At the bar.

where can/should i/we...Said bury Kai guessed "I, we should go**." or "I can be in**."

For example: where should we go for dinner tonight?(Should we go to dinner tonight?)

Compound forms of where, such as whereabouts, whereas, whereby, etc., all have independent meanings and usages.

3.where.

Where can also be used with other words and phrases to form some common collocations, such as:

Whereabouts e.g. Do you know the Whereabouts of John?(Do you know John's whereabouts?) ）

Wherever (no matter in **) e.g. you can find good food wherever you go(No matter where you go, you'll find good food.) ）

For example: i love chocolate, whereas my sister hates it(I love chocolate, but my sister doesn't.) ）

In short, where is a very commonly used word, and there are many uses and collocations in English, and mastering the common usages and collocations in it will help you better understand the English language of place inquiry and description.