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< h1 > < i class = "glyphicon glyphicon-leaf" > < / i > < code class = "mod" > lektor.db.< / code > < code class = "obj" > Expression< / code > < / h1 >
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< p > Expressions are used to filter down < a href = "../query/" class = "ref" > Query< / a > objects. They
can be passed to the < a href = "../query/filter/" class = "ref" > filter< / a > function in particular.< / p >
< p > The most basic expression is created by accessing the < a href = "../f/" class = "ref" > F< / a > object
which will return an expression that points to a field. Further manipulation
of it can create more expressive expressions. < code > F.name< / code > literally just means
that a field by that name exists and is set to a value.< / p >
< p > The query syntax is mostly the same in Python as well as in the Jinja 2
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templates, the main difference are < a href = "and/" class = "ref" > and< / a > and < a href = "or/" class = "ref" > or< / a > .< / p >
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< h2 id = "example" > Example< / h2 > < div class = "hll" > < pre > < span > < / span > < span class = "gp" > > > > < / span > < span class = "n" > p< / span > < span class = "o" > .< / span > < span class = "n" > children< / span > < span class = "o" > .< / span > < span class = "n" > filter< / span > < span class = "p" > ((< / span > < span class = "n" > F< / span > < span class = "o" > .< / span > < span class = "n" > name< / span > < span class = "o" > ==< / span > < span class = "s1" > ' foo' < / span > < span class = "p" > )< / span > < span class = "o" > |< / span > < span class = "p" > (< / span > < span class = "n" > F< / span > < span class = "o" > .< / span > < span class = "n" > name< / span > < span class = "o" > ==< / span > < span class = "s1" > ' bar' < / span > < span class = "p" > ))< / span > < span class = "o" > .< / span > < span class = "n" > all< / span > < span class = "p" > ()< / span >
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< span class = "go" > [< Page model=u' page' id=u' bar' > , < Page model=u' page' id=u' foo' > ]< / span >
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< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-flash" > < / i >
< a href = "ne/" > !=< / a >
< / h4 >
< p class = "summary" > Compares an expression to another by ensuring inequality.< / p >
< / div >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-flash" > < / i >
< a href = "lt/" > < < / a >
< / h4 >
< p class = "summary" > True if the left side is smaller than the right side.< / p >
< / div >
< / div >
< div class = "row" >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-flash" > < / i >
< a href = "le/" > < =< / a >
< / h4 >
< p class = "summary" > True if the left side is smaller or equal to the right side.< / p >
< / div >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-flash" > < / i >
< a href = "eq/" > ==< / a >
< / h4 >
< p class = "summary" > Compares an expression to another.< / p >
< / div >
< / div >
< div class = "row" >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-flash" > < / i >
< a href = "gt/" > > < / a >
< / h4 >
< p class = "summary" > True if the left side is larger than the right side.< / p >
< / div >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-flash" > < / i >
< a href = "ge/" > > =< / a >
< / h4 >
< p class = "summary" > True if the left side is larger or equal to the right side.< / p >
< / div >
< / div >
< div class = "row" >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-cog" > < / i >
< a href = "and/" > and()< / a >
< / h4 >
< p class = "summary" > True if both left and right side are true.< / p >
< / div >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-cog" > < / i >
< a href = "contains/" > contains()< / a >
< / h4 >
< p class = "summary" > Checks if an item contains another one.< / p >
< / div >
< / div >
< div class = "row" >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-cog" > < / i >
< a href = "endswith/" > endswith()< / a >
< / h4 >
< p class = "summary" > True if a string ends with another string (case insensitive).< / p >
< / div >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-cog" > < / i >
< a href = "endswith-cs/" > endswith_cs()< / a >
< / h4 >
< p class = "summary" > True if a string ends with another string (case sensitive).< / p >
< / div >
< / div >
< div class = "row" >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-cog" > < / i >
< a href = "or/" > or()< / a >
< / h4 >
< p class = "summary" > True if either left and right side are true.< / p >
< / div >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-cog" > < / i >
< a href = "startswith/" > startswith()< / a >
< / h4 >
< p class = "summary" > True if a string starts with another string (case insensitive).< / p >
< / div >
< / div >
< div class = "row" >
< div class = "col-md-6 child" >
< h4 >
< i class = "glyphicon glyphicon-cog" > < / i >
< a href = "startswith-cs/" > startswith_cs()< / a >
< / h4 >
< p class = "summary" > True if a string starts with another string (case sensitive).< / p >
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