query-generator.js

var Utils = require("../../utils")
  , util  = require("util")

tables = {}

function pgEscape(s) {
  s = Utils.escape(s)
  if (typeof s == 'string') s = s.replace(/\\"/g, '"')
  return s
}

module.exports = (function() {
  var QueryGenerator = {
    createTableQuery: function(tableName, attributes, options) {
      options = Utils._.extend({
      }, options || {})

      tables[tableName] = {}

      var query   = "CREATE TABLE IF NOT EXISTS <%= table %> (<%= attributes%>)"
        , primaryKeys = []
        , attrStr = Utils._.map(attributes, function(dataType, attr) {
            if (Utils._.includes(dataType, 'PRIMARY KEY')) {
              primaryKeys.push(attr)
              dataType = dataType.replace(/PRIMARY KEY/, '')
            }

            if (Utils._.includes(dataType, 'DATETIME')) {
              dataType = dataType.replace(/DATETIME/, 'TIMESTAMP')
            }

            if (Utils._.includes(dataType, 'TINYINT(1)')) {
              dataType = dataType.replace(/TINYINT\(1\)/, 'BOOLEAN')
            }

            if (Utils._.includes(dataType, 'DATETIME')) {
              dataType = dataType.replace(/DATETIME/, 'TIMESTAMP')
            }

            if (Utils._.includes(dataType, 'SERIAL')) {
              dataType = dataType.replace(/INTEGER/, '')
              dataType = dataType.replace(/NOT NULL/, '')
              tables[tableName][attr] = 'serial'
            }

            return attr + " " + dataType
          }).join(", ")
        , values  = {
            table: tableName,
            attributes: attrStr,
            engine: options.engine,
            charset: (options.charset ? "DEFAULT CHARSET=" + options.charset : "")
          }
        , pkString = primaryKeys.map(function(pk) {return pk}).join(", ")

      if(pkString.length > 0) values.attributes += ", PRIMARY KEY (" + pkString + ")"

      return Utils._.template(query)(values).trim() + ";"
    },

    dropTableQuery: function(tableName, options) {
      options = options || {}

      var query = "DROP TABLE IF EXISTS <%= table %>;"

      return Utils._.template(query)({table: tableName})
    },

    renameTableQuery: function(before, after) {
      var query = "ALTER TABLE <%= before %> RENAME TO <%= after %>;"
      return Utils._.template(query)({ before: before, after: after })
    },

    showTablesQuery: function() {
      return "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public';"
    },

    addColumnQuery: function(tableName, attributes) {
      var query      = "ALTER TABLE <%= tableName %> ADD COLUMN <%= attributes %>;"
        , attrString = Utils._.map(attributes, function(definition, attributeName) {
            return Utils._.template('<%= attributeName %> <%= definition %>')({
              attributeName: attributeName,
              definition: definition
            })
          }).join(', ')

      return Utils._.template(query)({ tableName: tableName, attributes: attrString })
    },

    removeColumnQuery: function(tableName, attributeName) {
      var query = "ALTER TABLE <%= tableName %> DROP COLUMN <%= attributeName %>;"
      return Utils._.template(query)({ tableName: tableName, attributeName: attributeName })
    },

    changeColumnQuery: function(tableName, attributes) {
      var query      = "ALTER TABLE <%= tableName %> ALTER COLUMN <%= attributes %>;"
      var attrString = Utils._.map(attributes, function(definition, attributeName) {
        return Utils._.template('<%= attributeName %> <%= attributeName %> <%= definition %>')({
          attributeName: attributeName,
          definition: definition
        })
      }).join(', ')

      return Utils._.template(query)({ tableName: tableName, attributes: attrString })
    },

    renameColumnQuery: function(tableName, attrBefore, attributes) {
      var query      = "ALTER TABLE <%= tableName %> RENAME COLUMN <%= attributes %>;"
      var attrString = Utils._.map(attributes, function(definition, attributeName) {
        return Utils._.template('<%= before %> TO <%= after %>')({
          before: attrBefore,
          after: attributeName,
        })
      }).join(', ')

      return Utils._.template(query)({ tableName: tableName, attributes: attrString })
    },

    selectQuery: function(tableName, options) {
      options = options || {}
      options.table = Array.isArray(tableName) ? tableName.map(function(tbl){return tbl}).join(", ") : tableName
      options.attributes = options.attributes && options.attributes.map(function(attr){
        if(Array.isArray(attr) && attr.length == 2)
          return [attr[0], attr[1]].join(' as ')
        else
          return attr.indexOf(Utils.TICK_CHAR)<0 ? attr : attr
      }).join(", ")

      options.attributes = options.attributes || '*'

      var query = "SELECT <%= attributes %> FROM <%= table %>"

      if(options.where) {
        options.where = QueryGenerator.getWhereConditions(options.where)
        query += " WHERE <%= where %>"
      }
      if(options.order) query += " ORDER BY <%= order %>"
      if(options.group) {
        options.group = options.group
        query += " GROUP BY <%= group %>"
      }
      if(options.limit) query += " LIMIT <%= limit %>"
      if(options.offset) query += " OFFSET <%= offset %>"

      query += ";"
      return Utils._.template(query)(options)
    },

    insertQuery: function(tableName, attrValueHash) {
      var query = "INSERT INTO <%= table %> (<%= attributes %>) VALUES (<%= values %>) RETURNING *;"

      returning = []
      Utils._.forEach(attrValueHash, function(value, key, hash) {
        if (tables[tableName] && tables[tableName][key]) {
          switch (tables[tableName][key]) {
            case 'serial':
              delete hash[key]
              returning.push(key)
              break
          }
        }
      });

      var replacements  = {
        table: tableName,
        attributes: Utils._.keys(attrValueHash).map(function(attr){return attr}).join(","),
        values: Utils._.values(attrValueHash).map(function(value){
          return pgEscape((value instanceof Date) ? Utils.toSqlDate(value) : value)
        }).join(",")
      }

      return Utils._.template(query)(replacements)
    },

    updateQuery: function(tableName, values, where) {
      var query = "UPDATE <%= table %> SET <%= values %> WHERE <%= where %>"
      var replacements = {
        table: tableName,
        values: Utils._.map(values, function(value, key){
          return key + "=" + pgEscape((value instanceof Date) ? Utils.toSqlDate(value) : value)
        }).join(","),
        where: QueryGenerator.getWhereConditions(where)
      }

      return Utils._.template(query)(replacements)
    },

    deleteQuery: function(tableName, where, options) {
      options = options || {}
      options.limit = options.limit || 1

      var query = "DELETE FROM <%= table %> WHERE <%= where %>"
      var replacements = {
        table: tableName,
        where: QueryGenerator.getWhereConditions(where),
        limit: pgEscape(options.limit)
      }

      return Utils._.template(query)(replacements)
    },

    addIndexQuery: function(tableName, attributes, options) {
      var transformedAttributes = attributes.map(function(attribute) {
        if(typeof attribute == 'string')
          return attribute
        else {
          var result = ""

          if(!attribute.attribute)
            throw new Error('The following index attribute has no attribute: ' + util.inspect(attribute))

          result += attribute.attribute

          if(attribute.length)
            result += '(' + attribute.length + ')'

          if(attribute.order)
            result += ' ' + attribute.order

          return result
        }
      })

      var onlyAttributeNames = attributes.map(function(attribute) {
        return (typeof attribute == 'string') ? attribute : attribute.attribute
      })

      options = Utils._.extend({
        indicesType: null,
        indexName: Utils._.underscored(tableName + '_' + onlyAttributeNames.join('_')),
        parser: null
      }, options || {})

      return Utils._.compact([
        "CREATE", options.indicesType, "INDEX", options.indexName,
        (options.indexType ? ('USING ' + options.indexType) : undefined),
        "ON", tableName, '(' + transformedAttributes.join(', ') + ')',
        (options.parser ? "WITH PARSER " + options.parser : undefined)
      ]).join(' ')
    },

    showIndexQuery: function(tableName, options) {
      var sql = "SHOW INDEX FROM <%= tableName %><%= options %>"
      return Utils._.template(sql)({
        tableName: tableName,
        options: (options || {}).database ? ' FROM ' + options.database : ''
      })
    },

    removeIndexQuery: function(tableName, indexNameOrAttributes) {
      var sql       = "DROP INDEX <%= indexName %> ON <%= tableName %>"
        , indexName = indexNameOrAttributes

      if(typeof indexName != 'string')
        indexName = Utils._.underscored(tableName + '_' + indexNameOrAttributes.join('_'))

      return Utils._.template(sql)({ tableName: tableName, indexName: indexName })
    },

    getWhereConditions: function(smth) {
      var result = null

      if(Utils.isHash(smth))
        result = QueryGenerator.hashToWhereConditions(smth)
      else if(typeof smth == 'number')
        result = 'id' + "=" + pgEscape(smth)
      else if(typeof smth == "string")
        result = smth
      else if(Array.isArray(smth))
        result = Utils.format(smth)

      return result
    },

    hashToWhereConditions: function(hash) {
      return Utils._.map(hash, function(value, key) {
         //handle qualified key names
        var _key   = key.split('.').map(function(col){return col}).join(".")
          , _value = null

      if(Array.isArray(value)) {
          _value = "(" + Utils._.map(value, function(subvalue) {
            return pgEscape(subvalue);
          }).join(',') + ")"

          return [_key, _value].join(" IN ")
      }
      else if ((value) && (typeof value == 'object')) {
        //using as sentinel for join column => value
        _value = value.join.split('.').map(function(col){return col}).join(".")
        return [_key, _value].join("=")
      } else {
          _value = pgEscape(value)
          return (_value == 'NULL') ? _key + " IS NULL" : [_key, _value].join("=")
        }
      }).join(" AND ")
    },

    attributesToSQL: function(attributes) {
      var result = {}

      Utils._.map(attributes, function(dataType, name) {
        //console.log(name, 'dataType:', dataType)
        if(Utils.isHash(dataType)) {
          var template     = "<%= type %>"
            , replacements = { type: dataType.type }

          if(dataType.type == 'TINYINT(1)') dataType.type = 'BOOLEAN'
          if(dataType.type == 'DATETIME') dataType.type = 'TIMESTAMP'

          if(dataType.hasOwnProperty('allowNull') && (!dataType.allowNull)) template += " NOT NULL"
          if(dataType.autoIncrement) template +=" SERIAL"
          if(dataType.defaultValue != undefined) {
            template += " DEFAULT <%= defaultValue %>"
            replacements.defaultValue = pgEscape(dataType.defaultValue)
          }
          if(dataType.unique) template += " UNIQUE"
          if(dataType.primaryKey) template += " PRIMARY KEY"

          result[name] = Utils._.template(template)(replacements)
        } else {
          result[name] = dataType
        }
      })

      return result
    },

    findAutoIncrementField: function(factory) {
      var fields = Utils._.map(factory.attributes, function(definition, name) {
        var isAutoIncrementField = (definition && (definition.indexOf('SERIAL') > -1))
        return isAutoIncrementField ? name : null
      })

      return Utils._.compact(fields)
    }
  }

  return Utils._.extend(Utils._.clone(require("../query-generator")), QueryGenerator)
})()